MGR_GUIDE

TOPS-20
TOPS-20
System Manager's Guide
System Manager's Guide

June 1990
| June 1990

This document is intended for the person who is
responsible for making final decisions for setting
up and maintaining the efficient operation of a
TOPS-20 installation.

Change bars in margins indicate material that has
been added or changed since the previous printing
of this manual.

OPERATING SYSTEM:
OPERATING SYSTEM: TOPS-20 (KL Model B) Version 7.0

digital equipment corporation
maynard, massachusetts

First Printing, September 1985
Revised, June 1988
| Revised, June 1990

The information in this document is subject to change without notice
and should not be construed as a commitment by Digital Equipment
Corporation. Digital Equipment Corporation assumes no responsibility
for any errors that may appear in this document.

The software described in this document is furnished under a license
and may only be used or copied in accordance with the terms of such
license.

No responsibility is assumed for the use or reliability of software on
equipment that is not supplied by Digital Equipment Corporation or its
affiliated companies.

| Copyright C 1985, 1988, 1990 Digital Equipment Corporation

The following are trademarks of Digital Equipment Corporation:

CI DECtape LA50 SITGO-10
DDCMP DECUS LN01 TOPS-10
DEC DECwriter LN03 TOPS-20
DECmail DELNI MASSBUS TOPS-20AN
DECnet DELUA PDP UNIBUS
DECnet-VAX HSC PDP-11/24 UETP
DECserver HSC-50 PrintServer VAX
DECserver 100 KA10 PrintServer 40 VAX/VMS
DECserver 200 KI Q-bus VT50
DECsystem-10 KL10 ReGIS
DECSYSTEM-20 KS10 RSX d i g i t a l

CONTENTS

PREFACE

CHAPTER 1 DOCUMENTATION

1.1 DOCUMENTS AVAILABLE FROM DIGITAL . . . . . . . . . 1-1
1.2 DOCUMENTS PREPARED AT YOUR INSTALLATION . . . . . 1-2
1.2.1 System Log . . . . . . . . . . . . . . . . . . . 1-3
1.2.2 Mountable Structure Sign-Up Log . . . . . . . . 1-6
1.2.3 System Access Request Form . . . . . . . . . . . 1-6
1.2.4 Operator Work Request Form . . . . . . . . . . . 1-9
1.2.5 Operator Shift Change Log . . . . . . . . . . . 1-9

CHAPTER 2 PREPARING FOR SOFTWARE INSTALLATION

2.1 SECURING THE COMPUTER ROOM . . . . . . . . . . . . 2-1
2.2 HANDLING USER REQUESTS . . . . . . . . . . . . . . 2-1
2.3 ORDERING SUPPLIES . . . . . . . . . . . . . . . . 2-2
2.4 SCHEDULING OPERATOR TASKS . . . . . . . . . . . . 2-2
2.5 SELECTING SYSTEM FEATURES . . . . . . . . . . . . 2-4

CHAPTER 3 AFTER SOFTWARE INSTALLATION

iii

3.4 CONSOLE FRONT-END FILES . . . . . . . . . . . . 3-25
3.5 TAILORING THE BATCH SYSTEM . . . . . . . . . . . 3-29
3.6 CHECKING THE SOFTWARE (UETP) . . . . . . . . . . 3-29
3.7 REMOTE PRINTERS . . . . . . . . . . . . . . . . 3-30
3.7.1 Remote Printing Requirements . . . . . . . . . 3-31
3.7.2 Defining DQS and LAT Printers . . . . . . . . 3-32
3.7.3 Setting DQS Printing Characteristics . . . . . 3-33
3.8 TERMINAL PRINTERS . . . . . . . . . . . . . . . 3-34

CHAPTER 4 CREATING STRUCTURES

CHAPTER 5 CREATING DIRECTORIES

5.1 HAVING THE OPERATOR CREATE AND MAINTAIN ALL
DIRECTORIES (CENTRAL CONTROL) . . . . . . . . . . 5-2
5.2 DELEGATING THE CREATION AND MAINTENANCE OF
DIRECTORIES TO PROJECT ADMINISTRATORS (PROJECT
CONTROL) . . . . . . . . . . . . . . . . . . . . . 5-2
5.3 COMBINING CENTRAL AND PROJECT CONTROL . . . . . . 5-3
5.4 CENTRAL AND PROJECT CONTROL DESCRIPTIONS . . . . . 5-3
5.4.1 Central Control . . . . . . . . . . . . . . . . 5-4
5.4.2 Central Control Using Subdirectories . . . . . . 5-7

5.4.3 Project Control . . . . . . . . . . . . . . . 5-14
5.4.4 Combined Central and Project Control . . . . . 5-22
5.5 ALLOCATING DISK STORAGE QUOTAS . . . . . . . . . 5-23
5.6 ENFORCING DISK STORAGE QUOTAS . . . . . . . . . 5-24
5.7 PROTECTING DIRECTORIES AND FILES . . . . . . . . 5-26
5.7.1 Directory and File Protection Digits . . . . . 5-26
5.7.2 Changing Directory and File Protection . . . . 5-29
5.8 ESTABLISHING GROUPS . . . . . . . . . . . . . . 5-29
5.9 GIVING USERS SPECIAL CAPABILITIES . . . . . . . 5-38
5.10 PRINTING DIRECTORY INFORMATION . . . . . . . . . 5-40

CHAPTER 6 CREATING ACCOUNTS

CHAPTER 7 SYSTEM BACKUP PROCEDURES

7.1 SAVING ALL FILES IN ALL DIRECTORIES . . . . . . . 7-2
7.1.1 Full Dumps . . . . . . . . . . . . . . . . . . . 7-3
7.1.2 Incremental Dumps . . . . . . . . . . . . . . . 7-3
7.1.3 Security of Backup Tapes . . . . . . . . . . . . 7-4
7.2 A COMMON BACKUP POLICY . . . . . . . . . . . . . . 7-4
7.3 MAGNETIC TAPE REQUIREMENTS . . . . . . . . . . . . 7-4
7.4 MAKING A SYSTEM CRASH TAPE . . . . . . . . . . . . 7-6
7.5 MAKING A CRASH TAPE USING BATCH . . . . . . . . . 7-8
7.6 SAVING THE CONSOLE FRONT-END FILE SYSTEM . . . . 7-10

CHAPTER 8 TAPE STORAGE

8.1 FILE ARCHIVING . . . . . . . . . . . . . . . . . . 8-2
8.1.1 Setting Up the System to Use File Archiving . . 8-3
8.1.2 What Happens When Users Archive Files . . . . . 8-3
8.1.3 What Happens When Users Retrieve Files . . . . . 8-5
8.1.4 When to Create Archive Tapes . . . . . . . . . . 8-5
8.1.5 Processing Retrieval Requests . . . . . . . . . 8-7
8.2 FILE MIGRATION . . . . . . . . . . . . . . . . . . 8-7
8.2.1 Setting Up the System to Use File Migration . . 8-8

CHAPTER 9 SYSTEM PROBLEMS/CRASHES

CHAPTER 10 SYSTEM PERFORMANCE

10.1 THE CLASS SCHEDULER . . . . . . . . . . . . . . 10-2
10.1.1 Overview . . . . . . . . . . . . . . . . . . . 10-2
10.1.2 Who Should Use the Class Scheduler? . . . . . 10-4
10.1.3 How to Begin Using the Class Scheduler . . . . 10-6
10.1.4 Procedures to Turn On the Class Scheduler . . 10-8
10.1.5 Changing Class Percentages During Timesharing 10-10
10.1.6 Disabling the Class Scheduler During
Timesharing . . . . . . . . . . . . . . . . . 10-11

10.1.7 Getting Information About Class Scheduler
Status . . . . . . . . . . . . . . . . . . . . 10-11
10.1.8 A Sample Session . . . . . . . . . . . . . . . 10-13
10.1.9 An Alternative to Using Accounts . . . . . . . 10-14
10.2 SCHEDULING LOW PRIORITY TO BATCH JOBS . . . . . 10-15
10.3 FAVORING INTERACTIVE VERSUS COMPUTE-BOUND
PROGRAMS . . . . . . . . . . . . . . . . . . . . 10-15
10.4 IMPROVING PROGRAM STARTUP TIME . . . . . . . . . 10-17
10.5 REINITIALIZING DISK PACKS . . . . . . . . . . . 10-18
10.6 DYNAMIC DUAL PORTING . . . . . . . . . . . . . . 10-19

CHAPTER 11 ACCESS CONTROLS

CHAPTER 12 THE COMMON FILE SYSTEM

12.1 OVERVIEW . . . . . . . . . . . . . . . . . . . . 12-1
12.1.1 CFS HARDWARE . . . . . . . . . . . . . . . . . 12-2
12.1.2 CFS SOFTWARE . . . . . . . . . . . . . . . . . 12-6
12.1.3 CFS USERS . . . . . . . . . . . . . . . . . . 12-7

vii

CHAPTER 13 LAT TERMINAL SERVERS

viii

INDEX

FIGURES

TABLES

PREFACE
PREFACE

_______ ______ _________ _____
The TOPS-20 System Manager's Guide is written for the person who is
responsible for establishing policies and procedures for a timesharing
and/or batch processing installation using the TOPS-20 Operating
System. Usually, this person is responsible for setting up and
____
maintaining both the system hardware and software. The Site
__________ _____ _______________ __________ ________ ______ ___
Management Guide, the TOPS-10/TOPS-20 Operator's Hardware Device and
___________ _____ _______ __________ _____
Maintenance Guide, and the TOPS-20 Operator's Guide provide you and
your operations people with the necessary information to maintain your
system hardware. These three manuals are referenced throughout this
guide.

This guide deals primarily with your system software. It contains
general suggestions for planning the installation of your software and
for setting up your computer room to begin operations. The guide
contains hints and suggestions for your system's operation, including
when, and many times why, particular functions or procedures should be
considered. It assumes that your system operator is responsible for
implementing many of the decisions you make. In most cases, where
lengthy implementation procedures are required, the appropriate
reference is noted.

Chapters 1 and 2 describe the documentation, system logs, and
special forms that you should have available to
you, and in some cases, to system users.
Chapter 2 also includes preliminary planning
functions that you can do before the software
is installed.

Chapter 3 describes the system directories and files that
your system contains immediately after you
install the software. It also describes the
mechanisms you can use to change the installed
TOPS-20 batch system and to test the integrity
of your newly installed or updated system. In
addition, it describes requirements for remote
printing and for printing on devices attached
to terminals.

Chapter 4 describes using your disk-pack and disk-drive
resources to set up disk structures in a way
that best suits your installation's needs. It
also includes guidelines for determining the
available disk space that you have to create
user directories.

Chapter 5 describes creating and maintaining directories.
It includes a detailed description of the three
methods of administration you can choose from
to control the creation and maintenance of
directories. It describes how to use directory
and file protection codes to expand or limit
the type of access users can have to
directories and files, and how to place users
and directories in groups so that users can
share files.

Chapter 6 describes the TOPS-20 accounting facility. This
description includes how to choose an
accounting scheme, how to create accounting
files, and how to set the system to begin
validating accounts.

Chapter 7 describes backing up your disk structures onto
magnetic tape soon after software installation.
It recommends the supplies needed and
procedures that you should follow to save all
your directories and files on a daily basis,
and how to create a system crash tape in the
event of a major problem with the file system.

Chapter 8 describes how you can use magnetic tapes to
store important files (file archiving) and to
save valuable disk space by copying
infrequently accessed files to tape (file
migration). It also describes how to give
control of tape drive usage to the system and
the operator (tape drive allocation), and how
to set up your system to use labeled tapes
(tape labeling).

xii

Chapter 9 describes the procedures you must follow in the
event that you have a problem with the file
system or that a user has lost the files in a
directory. It also describes using your system
crash tape and your daily backup tapes to
resolve these problems. In addition, it
describes how to prevent "offline" disks from
hanging user jobs, and discusses dumping memory
for nonfatal system errors.

Chapter 10 describes the tuning mechanisms that allow you
to change the behavior of your system. Each
description includes why you may want to use a
particular mechanism, how to use it, and the
effects it may have on your system.

Chapter 11 describes the access control mechanisms that
you can use to alter system policy decisions or
to increase security against unauthorized
system use. This chapter includes the type of
policy changes you may want to make at your
installation.

Chapter 12 describes the Common File System, a software
feature of TOPS-20. This chapter discusses the
rules, options, and restrictions associated
with sharing files among systems.

Chapter 13 describes the Local Area Transport (LAT)
software, for use with terminal servers in
Ethernet local area networks.

xiii

The following conventions and symbols are used throughout this guide:

Convention/Symbol Description
Convention/Symbol Description

n- n refers to the latest version of a particular
file, for example, 7-CONFIG.CMD.

UPPERCASE In user input representations, indicates
information that must be entered exactly as
shown.

lowercase In user input representations, indicates
variable information that is determined by you.

underlining Indicates the information that you must type at
your terminal.

() In user input representations, encloses guide
word information. Pressing the ESCAPE or
ALTMODE key on your terminal causes guidewords
to be printed by the computer.

Indicates you should press the RET or RETURN
key on your terminal. Unless otherwise noted,
pressing RETURN terminates all command or input
strings.

Indicates you should press the ESC key on your
terminal.

CTRL/key Indicates you should press the CTRL key on your
terminal. The CTRL key is always used in
conjunction with another key, for example,
CTRL/Z.

xiv

CHAPTER 1
CHAPTER 1

DOCUMENTATION
DOCUMENTATION

Section 1.1 describes the documentation provided by DIGITAL and
recommends the manuals with which you should be familiar to manage
your system. Section 1.2 describes adding your own documentation, for
example, special forms, to the documentation you receive from DIGITAL.
Be sure you have all available documentation convenient to your system
users.

1.1 DOCUMENTS AVAILABLE FROM DIGITAL
1.1 DOCUMENTS AVAILABLE FROM DIGITAL

All documentation for the TOPS-20 Operating System is contained in the
_______ ________ ________ ____
TOPS-20 Software Notebook Set. This notebook set contains information
pertaining to the most recent version of TOPS-20. It is organized
functionally to facilitate referencing manuals. Each manual contains
cross references to other manuals within the set that further explain
a subject.

This manual assumes that you are familiar with some of the manuals in
the notebook set. In particular, you should be familiar with the
_______ __________ _____ _______ ______ _____
information in the TOPS-20 Operator's Guide, the TOPS-20 User's Guide,
____________ _________ _______ _______________ __________
the DECSYSTEM-20 Technical Summary, the TOPS-10/TOPS-20 Operator's
________ ______ ___ ___________ _____ _______ ____ _____ _
Hardware Device and Maintenance Guide, and the TOPS-20 KL10 Model B
____________ _____
Installation Guide.

Any additional documents that you need depend on the configuration of
your system. For example, if your system has IBM emulation and
___
termination (DNxx), you should be familiar with the IBM
_____________________ ______
Emulation-Termination Manual. It includes installation procedures and
descriptions of the operator and user interfaces. If your system has
DECnet, you should be familiar with the various DECnet-20 manuals. If
you are using LAT terminal servers in an Ethernet local area network,
refer to the documentation that is provided with LAT terminal servers,
in addition to chapter 13 of this manual.

_______ ________ ________ ___
In addition to the TOPS-20 Software Notebook Set, you receive the
TOPS-20 Beware File Listing. It is distributed with the software

1-1
DOCUMENTATION
DOCUMENTATION

installation and distribution magnetic tapes. Before installing a new
version of the software on your system, read the Beware File. It
contains last-minute changes to the software that have not been
documented, and hints or suggestions for installing or using the new
software.

With each new system, you should also receive two stand-alone
documents, which are documents not included in the notebook set.
These manuals assist you in 1) preparing your site for the hardware
____ ___________ ______
installation, the Site Preparation Guide, and 2) maintaining and
____
reporting problems about your system's software and hardware, the Site
__________ ______
Management Guide.

NOTE

____
Your Sales Representative delivers the Site
___________ ______
Preparation Guide, and your Field Service
____ __________ ______
Representative delivers the Site Management Guide.

_______ ______ _________ _____
This manual (the TOPS-20 System Manager's Guide) deals primarily with
installing and maintaining the software on your system. Therefore, it
____ ___________ _____
is assumed that you have already used the Site Preparation Guide to
install your system hardware.

____ __________ _____
The Site Management Guide is designed for use by both you (along with
your operations people) and your Field Service Representative. You
should begin using this manual immediately after you install your
hardware. It contains schedules, procedures, and logs for recording
and evaluating all information pertinent to the operation and care of
the system. The manual belongs to DIGITAL, but it is kept and
maintained at your computer site. For added convenience and
organization, many system managers keep all their important system
____ __________ ______
information in the same binder as the Site Management Guide. For
example, they keep system logs and operator shift change information
in the same binder, along with other special forms. Section 1.2
describes several forms that you may include in a system log book or,
____ __________ ______
as suggested here, in the Site Management Guide.

DIGITAL places a major emphasis on the documentation provided to its
customers. The Software Publications Department continues to solicit
suggestions for improvement and corrections from the users of its
documentation. Encourage users to comment on the manuals you receive
with your system. For convenience, a Reader Comment Form is located
at the back of each manual.

1.2 DOCUMENTS PREPARED AT YOUR INSTALLATION
1.2 DOCUMENTS PREPARED AT YOUR INSTALLATION

Sections 1.2.1 through 1.2.5 describe some forms that may be useful at
your installation. A sample form is provided in each section.

1-2
DOCUMENTATION
DOCUMENTATION

1.2.1 System Log
1.2.1 System Log

Every system must have a system log for recording problems and
procedures relating to both hardware and software. All operators and
system programmers should record the following types of activities in
the log, along with the date, time, and their names:

o System backup procedures

o Beginning and ending of timesharing (for example, the times
the system was started and stopped for preventive maintenance
or repair)

o Problems in hardware or software AND the actions taken to
correct the problems (always save the CTY (operator terminal)
output or copy of the typescript)

o New or revised software installed

o New users or changes to existing user data or directories

o New structures or changes to existing structures

Most system problems are easier to solve (and, hence, less costly) if
____ __________
you keep an accurate record of all activities. The Site Management
_____
Guide has a section set aside for system log information. This
section contains preprinted forms that you can use to record system
log information, or you can design your own forms. You can store
____ __________ _____
these forms in the Site Management Guide or in a separate binder.

You should design your log so that it is easy to use and read.
Remember, you are likely to have the most problems when the system is
new, so NOW is the time to start using the log. The following two
pages contain sample left- and right-hand pages of a log book. The
left-hand page (Figure 1-1) contains information concerning hardware
maintenance; the right-hand page (Figure 1-2) is a problem report,
containing:

o The time of the entry

o A "Y" or "N" answer to whether the system had to be reloaded

o The name of the person making the entry

o A few words describing the nature of the activity

o A record of calls to Digital Field Service (F/S)

o A description of the device or program causing the problem

o Remarks about the entry

1-3
DOCUMENTATION
DOCUMENTATION

Figure 1-1: Sample System Log (Hardware Maintenance)
Figure 1-1: Sample System Log (Hardware Maintenance)

1-4
DOCUMENTATION
DOCUMENTATION

Figure 1-2: Sample System Log (Problem Report)
Figure 1-2: Sample System Log (Problem Report)

1-5
DOCUMENTATION
DOCUMENTATION

1.2.2 Mountable Structure Sign-Up Log
1.2.2 Mountable Structure Sign-Up Log

In addition to keeping the system log, you should also record requests
from users to mount structures. (Chapter 4 describes how to set up
and use structures.) Without a formal scheduling procedure, some users
may monopolize the use of a structure and frustrate other users, who
do not have the opportunity to mount and use their structures, usually
because there are no disk drives available. To avoid this situation,
set up a procedure whereby users inform the operator when they need to
use a structure. The operator can then schedule the length of time
specified on the request log. On a busy day, when many users are
issuing mount requests for structures, the operator checks the log
before granting or denying the mount requests. This scheduling allows
you to service many requests for mounting structures in a fair and
orderly manner. The sample mountable structure sign-up log shown in
Figure 1-3 contains:

o The scheduled mounting time

o The scheduled time needed to use the structure

o The actual time the structure was mounted

o The actual time the structure was removed

o The name of the user who initiated the request

o The structure name (or pack ID)

o A column for any special instructions or notes

Remember that this log is only a sample; you should design a form that
best suits your own requirements.

1.2.3 System Access Request Form
1.2.3 System Access Request Form

Some installations have many users requesting access to the system for
the first time. You need standard information from these users before
you can process their requests and create directories for them. For
example, you must know which system they need to access (if you have
more than one system), their names, selected passwords, departments,
accounts, etc. You can organize these requests by providing a System
Access Request Form that is kept in an easy-to-access area, perhaps
outside the computer room. You can require signatures of department
managers on the access form to ensure that prospective users have
approval to charge computer usage to accounts. Figure 1-4 is a sample
of a system access request form.

If you are using CFS-20 software, refer to Chapter 12, The Common File
System, for further considerations in assigning users to systems.

1-6
DOCUMENTATION
DOCUMENTATION

Figure 1-3: Sample Mountable Structure Sign-Up Log
Figure 1-3: Sample Mountable Structure Sign-Up Log

1-7
DOCUMENTATION
DOCUMENTATION

SYSTEM ACCESS REQUEST

SYSTEM NAME:_______________________________ DEPT.:____________________
YOUR NAME:_________________________________ ACCT.:____________________
PROJECT:______________________________________________________________

PERM. ACCESS? ____YES ____NO (FROM:______________TO:______________)

SUPERVISOR:___________________________ MGR:___________________________
SIGNATURE SIGNATURE
----------------------------------------------------------------------

DIRECTORY NAME (1-39 CHAR.):__________________________________________
__
PASSWD.:___________________ DIR. PROT.(DEF.777700) |__| OTHER:________
__ __
*DO YOU REQUIRE PRIVILEGES ON THE SYSTEM? |__| N |__| Y (TYPE:______)
__ __
DO YOU WANT TO CREATE SUBDIRS.? |__| N |__| Y (HOW MANY?_____ MAX.= 8)
__
DO YOU WANT TO BE IN A GROUP WITH OTHER USERS OR DIRECTORIES? |__| N
__
|__| Y (NAME OF USER(S) OR DIR.(S):__________ ___________ ___________)

BRIEFLY DESCRIBE THE TYPE OF WORK YOU WILL PERFORM. FOR EXAMPLE,
CREATING AND EDITING FILES, APPLICATIONS PROGRAMMING, COMPILER
PROGRAMMING, ETC._____________________________________________________
----------------------------------------------------------------------
OPERATIONS USE ONLY
DIR. PASSWD. STRUCTURE WORKING QUOTA PERM. QUOTA

________ ___________ _______________ _________________ ___________

USER GROUP DIR. GROUP ACCOUNT

_________________________ __________________________
_________________________ __________________________ ___________

SUBDIRECTORIES SCHED. CLASS PRIVILEGES DATE CREATED

____________________ ________________ ________________ ____________

COMMENTS:_____________________________________________________________
*MUST BE APPROVED BY OPERATIONS MANAGEMENT

Figure 1-4: System Access Request
Figure 1-4: System Access Request

1-8
DOCUMENTATION
DOCUMENTATION

1.2.4 Operator Work Request Form
1.2.4 Operator Work Request Form

You may want a form that allows users to request work from the
operator. Examples of requests made to the operator are initializing
tapes, transferring files between systems, and making changes to
directories. You should set up a procedure for handling these
requests. Figure 1-5 is a sample of an operator work request form.

1.2.5 Operator Shift Change Log
1.2.5 Operator Shift Change Log

You may want to set up a binder to contain operator shift change
information. Each operator records new procedures, or special
instructions that the incoming operator needs to know. The incoming
operator reads the operator shift log before starting the new shift.
For example, the first shift operator changes the procedure for
storing tapes, and records the new procedure in the shift change log.
The information in the shift change log should not concern problems
with the system, but should contain important information about the
system or the computer room. The incoming operator still reads the
system log book to determine the status of the system and any problems
that have occurred during the previous shift. Figure 1-6 is a sample
of an operator shift change log.

1-9
DOCUMENTATION
DOCUMENTATION

Figure 1-5: Operator Work Request
Figure 1-5: Operator Work Request

1-10
DOCUMENTATION
DOCUMENTATION

Figure 1-6: Operator Shift Change Log
Figure 1-6: Operator Shift Change Log

1-11

2-1

CHAPTER 2
CHAPTER 2

PREPARING FOR SOFTWARE INSTALLATION
PREPARING FOR SOFTWARE INSTALLATION

You can establish many of the policies and procedures for your
computer site before you install the software. It may help you later
if some of the preliminary decisions and preparations are done before
you begin setting up the system and handling requests from users. The
following suggestions for preparing your installation are not
all-inclusive. Some TOPS-20 installations have specific requirements
or restrictions that are not considered here. You can use this list
as a guideline for the types of decisions you can make in the early
stages of setting up your computer site.

2.1 SECURING THE COMPUTER ROOM
2.1 SECURING THE COMPUTER ROOM

Select the type of computer room security you need and a method of
enforcement. Many system managers do not allow non-operations people
to enter the computer room. Establish an open- or closed-door policy,
and notify users of your policy. If you decide on a closed-door
policy, notify users of the procedures that they should use to contact
you (or the operator) and to submit their job requests.

2.2 HANDLING USER REQUESTS
2.2 HANDLING USER REQUESTS

Determine how user requests will be handled. You can handle jobs on a
first-come basis, or on a priority basis. You can set up request
boxes outside the computer room that the operator checks regularly.
You can also establish a location where users can leave disks and
tapes for the operator to mount. Post a sign-up sheet so that users
can specify the time they need the tape or disk mounted. Chapter 1
describes sample forms that can be completed by users to request
initial access to the system and to request that work be done by the
operator.

2-1
PREPARING FOR SOFTWARE INSTALLATION
PREPARING FOR SOFTWARE INSTALLATION

2.3 ORDERING SUPPLIES
2.3 ORDERING SUPPLIES

Assign someone the responsibility for ordering paper supplies,
ribbons, cards, and magnetic tapes. Chapter 7 provides an estimate of
the number of tapes you should have to begin a backup procedure
immediately after you install the software. Be sure you have enough
CTY (operator terminal) and line printer paper to begin operations.

2.4 SCHEDULING OPERATOR TASKS
2.4 SCHEDULING OPERATOR TASKS

The operator performs tasks either on a regular basis or on an
as-needed basis. Decide which operator tasks will be performed on a
regular schedule. Be sure to include hardware, software, and
documentation related tasks. These regularly scheduled tasks can be
performed daily, weekly, or monthly.

The following lists are samples of hardware- and software-related
tasks that your operator may perform.

Hardware-Related Tasks
Hardware-Related Tasks

Regular Schedule As-Needed Schedule
Regular Schedule As-Needed Schedule
__________________________________________________________________

Clean tops of disk drives. Replenish paper in the line
printer.

Clean magnetic tape drives. Remove reports from the line
printer and distribute (perhaps
to mail boxes).

Vacuum line printer to remove Replenish paper in operator's
paper chad. console.

Load mountable structures Physically load and unload
according to a schedule. magnetic tape and disk drives.
__________________________________________________________________

2-2
PREPARING FOR SOFTWARE INSTALLATION
PREPARING FOR SOFTWARE INSTALLATION

Regular Schedule As-Needed Schedule
Regular Schedule As-Needed Schedule

Software-Related Tasks
Software-Related Tasks
__________________________________________________________________

Bring up system after weekly Bring up system after a crash.
maintenance.

Run scheduled batch production Maintain the batch system for
jobs. users.

Save the contents of disk on Save special disk areas on
magnetic tape. magnetic tape.

Create a system "crash" tape Restore selected user disk
for backup. areas as needed.

Run the SPEAR program for daily Interact with users.
error analysis.

Submit a daily control file for Create and update user
accounting. directories.

Create the Message-of-the-Day Monitor disk space.
with the MAIL program.
__________________________________________________________________

Establish a location for keeping the hard-copy output from the CTY.
Your Field Service Representative needs this information if you have
problems with your system. Have the operator tear off the copy and
store it daily.

Documentation-related tasks include:

o keeping a hand-written log of system activities (System Log)

o recording operator shift change information (Operator Shift
Change Log)

o coordinating the mounting and dismounting of structures
(Mountable Structure Sign-up Log)

Chapter 1 describes creating a system log, an operator shift change
log, and a mountable structure sign-up log.

2-3
PREPARING FOR SOFTWARE INSTALLATION
PREPARING FOR SOFTWARE INSTALLATION

2.5 SELECTING SYSTEM FEATURES
2.5 SELECTING SYSTEM FEATURES

Determine the system features you want to enable during software
installation. When you install the software, you create a file called
n-CONFIG.CMD. This file is read by a start-up program (n-SETSPD) when
the system is started for the first time and each subsequent time that
you reload and start the system. The n-CONFIG.CMD file defines the
line speeds for your terminals and many system parameters. Most of
the decisions you must make concerning the parameters in this file are
described throughout this manual. As you read each chapter, you can
list the parameters that you want to place in the n-CONFIG.CMD file.
Many system managers choose to introduce new pieces of software
slowly. Therefore, you may want to disable some of the parameters
until you have run the new software for awhile. You can edit the
n-CONFIG.CMD file to add new software features to the system. You
should edit the file at a convenient time before you reload the
system. Then, when the system restarts, the new software features are
enabled.

NOTE

| The operator can run the n-SETSPD program
| interactively during timesharing to override many of
_______
| the n-CONFIG.CMD options, as described in the TOPS-20
__________ _____
| Operator's Guide.

Chapters 3 through 13 describe setting up and maintaining your system.
Read these chapters thoroughly. They contain important information to
help you make decisions both before and after you install the
software.

2-4

CHAPTER 3
CHAPTER 3

AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

3.1 OVERVIEW
3.1 OVERVIEW

After you install the TOPS-20 software, your system contains all the
directories and files necessary for you to start preparing for
timesharing and batch processing. This chapter describes the
directories, files, and system logical names created during software
installation. Also included are suggestions for creating additional
directories and logical names to assist you and system users.

3.2 SPECIAL SYSTEM DIRECTORIES
3.2 SPECIAL SYSTEM DIRECTORIES

You initialize the file system during software installation. At this
time, the system automatically creates nine directories on the disk
that you defined as the system structure. These directories are:

Sections 3.2.1 through 3.2.7 describe these directories and their use.
Section 3.2.8 describes additional directories you can create and how
they are useful.

Chapter 5 also describes creating directories and discusses the
structure of directories.

3-1
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

3.2.1
3.2.1

The contains a separate file for each first-level
directory on the system structure as follows:

STR:
--------------------------------------------------
| | |
| | |
STR: ... STR: ... STR:

(where STR: is the name of the structure).

The is the most important directory created. Without
_____
it, directories and files cannot be accessed. You must NEVER modify
this directory. The system maintains a backup copy of
that can be accessed if the original copy is
destroyed. (Refer to Section 9.3, RESTORING .)

Each structure you create in addition to the system structure has a
. The on any structure points to all
the first-level directories created under the .

After you install the software, give the DIRECTORY command for
. The output on your terminal appears similar to the
example below. Note that each directory is a file in the
. The differences between this list and the one on
your terminal depend on the model system you have and the type of
unbundled software you have purchased.

_________ _________________________
$DIRECTORY (OF FILES) STR:

STR:
ACCOUNTS.DIRECTORY.1
BACKUP-COPY-OF-ROOT-DIRECTORY.IMAGE.1
BOOTSTRAP.BIN.1
DSKBTTBL..1
FRONT-END-FILE-SYSTEM.BIN.1
INDEX-TABLE.BIN.1
NEW-SUBSYS.DIRECTORY.1
NEW-SYSTEM.DIRECTORY.1
OPERATOR.DIRECTORY.1
ROOT-DIRECTORY.DIRECTORY.1
SPOOL.DIRECTORY.1
SUBSYS.DIRECTORY.1
SYSTEM.DIRECTORY.1
SYSTEM-ERROR.DIRECTORY.1
UETP.DIRECTORY.1

Total of 14 Files

3-2
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

3.2.2
3.2.2

The directory contains data and program files that the system
uses during normal operation. Table 3-1 lists many of the files that
appear in this directory.

Table 3-1: Files
Table 3-1: Files

__________________________________________________________________

File Name Explanation
File Name Explanation
__________________________________________________________________

0DUMP11.BIN Contains a dump of front-end memory
after the front end crashes.

2060-MONBIG.EXE The smallest runnable non-ARPANET
monitor.

2060-MONMAX.EXE The largest runnable non-ARPANET
monitor.

n-CONFIG.CMD Contains definitions of line speeds,
system logical names, printer VFU
files, magnetic tape logical unit
numbers, DECnet parameters, and
additional system-dependent
parameters. These system parameters
are set every time the system starts.
The value n equals the latest release
of TOPS-20.

n-PTYCON.ATO Contains the commands that are given
automatically at the operator's
console every time the system starts.
You may modify this file to suit your
own installation. The value n equals
the latest release of TOPS-20.

n-SETSPD.EXE Program that reads the n-CONFIG.CMD
file and sets up the parameters that
it contains. The value n equals the
latest release of TOPS-20.

n-SYSJOB.EXE Program that runs in a process created
by the monitor and takes commands from
the file n-SYSJOB.RUN. The value n
equals the latest release of TOPS-20.

3-3
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-1: Files (Cont.)
Table 3-1: Files (Cont.)

File Name Explanation
File Name Explanation

n-SYSJOB.RUN Contains commands that SYSJOB
processes. The value n equals the
latest release of TOPS-20.

ACCOUNTS-TABLE.BIN Contains the information necessary to
validate accounts.

AN-MONBIG.EXE The smallest ARPANET timesharing
monitor.

AN-MONDCN.EXE A monitor that includes ARPANET and
DECnet.

AN-MONMAX.EXE The largest ARPANET timesharing
monitor.

BUGS.MAC Contains a list of all BUGHLT, BUGINF,
and BUGCHK messages.

CHECKD.EXE Program that creates structures and
checks file-system consistency.

COMAND.CMD An installation-specific systemwide
COMAND.CMD file.

DEVICE-STATUS.BIN Contains status information for tape
drives, disk drives, and disk
structures. It is maintained by
MOUNTR.

DUMP.CPY Contains a copy of main memory at the
time of the last system crash. It is
copied from DUMP.EXE to maintain a
history of crashes. This file is
written by the n-SETSPD program when
the system is rebooted.

DUMP.EXE Contains a copy of main memory at the
time of the last system crash. You
must have this file to get a system
dump after a crash.

ERRMES.BIN Contains binary system error messages.

EXEC.EXE The TOPS-20 Command Processor.

3-4
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-1: Files (Cont.)
Table 3-1: Files (Cont.)

File Name Explanation
File Name Explanation

FEDDT.EXE A DDT program used for debugging the
front end.

HOSTS.TXT Defines ARPANET host names and their
number translations.
|
| INTERNET.ADDRESS Defines the system's TCP/IP address
| for AN20, CI20, and NIA20 interfaces.
|
| INTERNET.GATEWAYS Defines the network gateways for
| reaching host systems on remote
| networks.
|
| INTERNET.NAMESERVERS Lists name server hosts.

IPALOD.EXE Program that loads the CI20 microcode.
(The microcode is contained in the
file.) After the loading has
completed, TOPS-20 starts the CI.

KNILDR.EXE Program that loads the NIA20
microcode. (The microcode is contained
in the file.) It is run automatically
at system startup to start the NI.

LOGOUT.CMD An installation-specific systemwide
LOGOUT.CMD file.

MONITR.EXE The current monitor.

MONNAM.TXT Contains the monitor name printed at
the beginning of the system greeting
line.

PROGRAM-NAME-CACHE.TXT Contains a list of the programs that
should be loaded into the program-name
cache. Read by the MAPPER program.

REAPER.CMD Contains a list of default commands to
REAPER. The REAPER program reads this
file each time it is run.

3-5
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-1: Files (Cont.)
Table 3-1: Files (Cont.)

File Name Explanation
File Name Explanation

RSX20F.MAP Contains symbol locations for the
front-end processor. It is used by the
FEDDT program.

SYSJOB.HLP Contains information about the SYSJOB
program.

SYSTEM.CMD Contains OPR commands and is read by
the OPR program at system startup.

TAPNAM.TXT Text file that contains the
installation identifier that is
written on VOL1 labels for labeled
tapes.

TGHA.EXE Program that analyzes and corrects MOS
memory problems.

TGHA.HLP Contains information about the TGHA
program.

TOPS-20.DOC Text file that contains summary
information about the latest release
of TOPS-20.
__________________________________________________________________

3.2.3 Restoring the Directory
3.2.3 Restoring the Directory

If the contents of are accidentally lost or destroyed, you
can restore the directory from the TOPS-20 Installation Tape or your
latest system backup tape. (Refer to Chapter 7 for information about
creating system backup tapes.) Use the procedure below to restore
directory. If you have enabled tape drive allocation, use
the MOUNT command instead of the ASSIGN command. (Refer to Section
8.3 for information about using tape drive allocation.)

1. Mount the appropriate tape (in this example, it is on drive
MTA0:).

2. Give the following commands at your terminal.

______ _____
@ENABLE (CAPABILITIES)
______ _____ _____
$ASSIGN (DEVICE) MTA0:
____ _____ _ _____ _____
$SKIP (DEVICE) MTA0: 4 FILES
___ _____ _____
$RUN (PROGRAM) MTA0:

3-6
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

____ _____ _____
DUMPER> TAPE (DEVICE) MTA0:
_______ _____________ ________ _____
DUMPER> RESTORE (TAPE FILES) DSK*:<*>*.*.* (TO)

DUMPER TAPE #1 , , FRIDAY 1-NOV-88 330
LOADING FILES INTO

END OF SAVESET
____ _____
DUMPER>EXIT
$

3.2.4
3.2.4

The directory contains system programs (and their help files)
that the user may want to run. The directory protection code set for
prevents users from changing the files in this directory.
Many of the file protections require users to enable WHEEL or OPERATOR
capabilities to use the files. (Refer to Chapter 5 for information
about directory and file protections and special capabilities.) Table
3-2 lists the programs and files commonly placed in . An
asterisk precedes all unbundled software.

Table 3-2: STR: Files
Table 3-2: STR: Files

__________________________________________________________________

Programs Explanation
Programs Explanation
__________________________________________________________________

ACTGEN.EXE Program that takes information from accounting
files and creates the account validation data
base.

ACTGEN.HLP Contains information about the ACTGEN program.

ACTSYM.UNV A file of universal symbols for USAGE accounting
programs.

ANAUNV.UNV A file of ARPANET universal symbols.

*B362LB.REL BLISS functions needed to rebuild the Record
Management Services facility (RMS-20) from
AUTOPATCH.

*BASIC.EXE The BASIC compiler.

BATCON.EXE Program that controls batch jobs.

CDRIVE.EXE Program that controls card readers.

3-7
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

CHECKD.EXE Program that creates structures and checks
file-system consistency (same as in ).

CHECKD.HLP Contains information about the CHECKD program.

CHKPNT.EXE Program that makes accounting entries in the file
CHECKPOINT.BIN.

CHKPNT.HLP Contains information about the CHKPNT program.

CMD.REL A library file of routines for the COMND monitor
call.

CMD.UNV A file of universal symbols for the COMND monitor
call.

*COBDDT.HLP Contains information about COBDDT.

*COBDDT.REL The COBOL debugging program.

*COBOL.EXE The COBOL compiler.

*COBOL.HLP Contains information about the COBOL compiler.

CREF.EXE Program that produces a cross-reference listing.

CREF.HLP Contains information about the CREF program.

DIL.LIB A library file of data definitions for COBOL
programs that use the Data Interchange Library
(DIL) facility.

DIL.REL The DIL subroutines.

DILV7.FOR Contains data definitions for FORTRAN programs
that use DIL.

DITV7.FOR Contains data definitions for FORTRAN programs
that use the data transmission component of DIL.

DIXV7.FOR Contains data definitions for FORTRAN programs
that use the data conversion component of DIL.

DLUSER.EXE Program that saves and restores the directory
parameters.

DLUSER.HLP Contains information about the DLUSER program.

3-8
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

DUMPER.EXE Program that saves and restores files to and from
magnetic tape.

DUMPER.HLP Contains information about the DUMPER program.

DX20LD.EXE Program that loads DX20 microcode.

DXMCA.ADX Microcode for DX20 tape subsystem controller.

EDDT.REL A component of the debugging program for the
TOPS-20 monitor.

EDIT.EXE A line-oriented text editor.

EDIT.HLP Contains information about the EDIT program.

FE.EXE Program that is used when copying files from the
front-end file system to the TOPS-20 file system
and vice versa.

FE.HLP Contains information about the FE program.

FEDDT.EXE The debugging program for the front end.

FILCOM.EXE Program that compares the contents of two files.

FILCOM.HLP Contains information about the FILCOM program.

FILDDT.EXE A DDT program used for examining the contents of
system dumps (DUMP.CPY).

*FORDDT.HLP Contains information about the FORDDT program.

*FORDDT.REL The FORTRAN debugging program.

FORMAT.EXE Program used to format RP04/RP06 disk packs while
the system is in timesharing mode.

FORMAT.HLP Contains information about the FORMAT program.

*FOROTS.EXE The FORTRAN object-time system (operating system
interface).

*FORTRA.EXE The FORTRAN compiler.

GALGEN.EXE Program that creates the parameter file (GALCNF)
for building the GALAXY programs.

3-9
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

GLOBS.UNV A file of universal symbols for the TOPS-20
monitor.

GLXLIB.EXE Object-time system used by the GALAXY programs.

HELP.HLP Contains information about the HELP command.

*IBMSPL.EXE Spooling program that sends IBM-batch-job files
to remote IBM host and retrieves the output.

INFO.EXE Program that gives information to programs using
IPCF.

*ISAM.EXE Program that maintains COBOL single-key indexed
sequential files.

*ISAM.HLP Contains information about the ISAM program.

KDDT.REL A component of the debugging program for the
TOPS-20 monitor.

KNILDR.EXE Program that loads the NIA20 microcode.

LCPORN.REL The LCP subprocess to the OPR program.

LCPTAB.REL The LCP command table.

*LIBARY.EXE Program that creates, maintains, and lists the
contents of COBOL library files.

*LIBARY.HLP Contains information about the LIBARY program.

*LIBO12.EXE The COBOL object-time system (operating system
interface).

*LIBOL.REL Contains the COBOL library subroutines.

LINK.EXE Program that loads relocatable binary programs.

LINK.HLP Contains information about the LINK program.

LISSPL.EXE Cluster LPTSPL listener that receives print
requests from remote cluster LPTSPLs and forwards
the requests to QUASAR.

LP64.RAM Translation RAM file for a 64-character line
printer. Read by n-SETSPD.

3-10
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

LP96.RAM Translation RAM file for a 96-character line
printer. Read by n-SETSPD.

LPTSPL.EXE Program that controls output to local line
printers as well as TTY, LAT, DQS, and cluster
printers.

MACREL.REL Run-time file for macros in MACSYM.

MACRO.EXE The MACRO assembler.

MACRO.HLP Contains information about the MACRO assembler.

MACSYM.UNV Contains system macros.

MS.EXE Program that sends messages to users.

MS.HLP Contains information about the MAIL program.

MS.EXE Program that receives mail from the MAIL program
and places it in the appropriate mailbox.

MAKDMP.EXE Program that produces a standard DUMP.EXE file in
.

MAKLIB.EXE Program that creates relocatable subroutine
libraries.

MAKLIB.HLP Contains information about the MAKLIB program.

MAKRAM.EXE Program that creates a translation RAM file for
line printers.

MAKRAM.HLP Contains information about the MAKRAM program.

MAKVFU.EXE Program that creates a vertical formatting unit
(VFU) file.

MAKVFU.HLP Contains information about the MAKVFU program.

MAPPER.EXE Program that loads the program-name cache. (Refer
to Section 10.4, Improving Program Startup Time.)

MDDT.REL A component of the debugging program for the
TOPS-20 monitor.

3-11
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

MONSYM.REL Object file that contains monitor call symbol
definitions.

MONSYM.UNV Contains symbol definitions for monitor calls.

MOUNTR.EXE Program that mounts tapes and structures.

MSCPAR.UNV A file of universal symbols used to build the
MSCP component of the TOPS-20 monitor.

NEBULA.EXE The cluster GALAXY message router between nodes
in a cluster.

*NFT.EXE DECnet file transfer program.

*NFT.HLP Contains information about the NFT.EXE program.

*NMLT20 DECnet program that performs the network control
program functions.

NORMAL.VFU Vertical formatting unit file for line printers.

OPR.EXE Program that the operator uses to interface with
all jobs and devices on the system.

OPR.HLP Contains information about the OPR program.

ORION.EXE Program that processes messages sent by the OPR,
MOUNTR, LPTSPL, QUASAR, EXEC, etc. programs.

OVRLAY.REL Overlay manager for the LINK program.

PA1050.EXE The TOPS-10 Compatibility Package.

PAT.EXE Version of PA1050 that can be used in debugging.

PHYPAR.UNV A file of universal symbols for TOPS-20
input/output programs.

PLEASE.EXE Program that establishes a dialog with the
operator.

PROLOG.UNV A file of universal symbols used to build the
TOPS-20 monitor.

PTYCON.EXE Program that controls many jobs from a single
terminal.

3-12
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

PTYCON.HLP Contains information about the PTYCON program.

QUASAR.EXE Program that does the central queuing and
scheduling for the batch system.

RDMAIL.EXE Program that allows a user to read mail sent with
the MAIL program.

RDMAIL.HLP Contains information about the RDMAIL program.

REAPER.EXE Program that marks files for migration to
magnetic tape.

REAPER.HLP Contains information about the REAPER program.

*RERUN.EXE Restarts COBOL programs.

*RERUN.HLP Contains information about the RERUN program.

RETRFB.SPE Contains SPEAR report templates.

RFB.EYE Contains internal definitions for the RETRIEVE
function of the SPEAR program.

RMS.EXE RMS-20 used in Section 0 of memory to get
XRMS.EXE.

RMSCOB.EXE RMS-20 used by COBOL V12B programs.

RMSFAL.EXE Program that 'listens' for DECnet file transfers.

RMSINI.REL Routine called by BLISS and MACRO programs to
initialize RMS-20.

RMSINT.R36 Unsupported BLISS interface file for RMS-20.

RMSINT.UNV MACRO interface file for RMS-20.

RMSUTL.EXE The RMS-20 file maintenance utility.

RSXFMT.EXE Utility program used for converting TOPS-20 files
to a format used by the front end and vice versa.

RSXFMT.HLP Contains information about the RSXFMT program.

RUNOFF.EXE Program that helps with text preparation.

3-13
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

RUNOFF.HLP Contains information about the RUNOFF program.

SCAPAR.UNV A parameter file of symbols for the SCA
inter-system communication routines.

SDDT.EXE DDT debugger for programs without a symbol table.

*SELOTS.EXE Program that interfaces between the COBOL
language and the COBOL object-time system
(LIBOL). (It is used with versions of COBOL up to
and including version 11.)

SERCOD.UNV Contains definitions for the SYSERR error codes.

*SIX12.REL The BLISS debugger.

*SORT.EXE Program that sorts files record by record.

*SORT.HLP Contains information about the SORT program.

SPRINT.EXE Program that creates batch jobs from card input.

SPROUT.EXE Output spooler for card punch, paper tape punch,
and plotter.

SPEAR.EXE Segment of SPEAR program.

SPRRET.EXE Segment of SPEAR program.

SPRSUM.EXE Segment of SPEAR program.

SYSJOB.HLP Contains information about the SYSJOB program.

SYSTAP.CTL Control file that creates a system backup tape.

TCX.EXE A DIGITAL Standard Runoff index utility.

TCX.HLP Contains information about the TCX utility.

TERMINAL.HLP Contains information about the TERMINAL command.

TOC.EXE A DIGITAL Standard Runoff utility for creating a
table of contents.

TOC.HLP Contains information about the TOC utility.

TV.EXE A character-oriented text editor.

3-14
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

Table 3-2: STR: Files (Cont.)
Table 3-2: STR: Files (Cont.)

Programs Explanation
Programs Explanation

UDDT.EXE DDT debugger for programs with a symbol table.

ULIST.EXE Program for printing information about
directories and users.

ULIST.HLP Contains information about the ULIST program.

VERIFY.EXE Program that is used during software installation
to determine the integrity of files. It verifies
checksums and version numbers of the .EXE files.

WATCH.EXE Program for observing system performance.

WATCH.HLP Contains information about the WATCH program.

*XPORT.REL Library containing the BLISS transportable I/O,
memory, and string functions.

XRMS.EXE RMS-20 library that is mapped to an extended
(nonzero) section for execution of RMS functions.
__________________________________________________________________

NOTE

All the .HLP files can be displayed using the HELP
command; for example, the command @HELP WATCH displays
the WATCH.HLP file.

3-15
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

3.2.5 Restoring the Directory
3.2.5 Restoring the Directory

If the contents of are accidentally lost or destroyed, you
can restore the directory from the TOPS-20 Installation Tape or your
latest system backup tape. (Refer to Chapter 7 for information about
creating system backup tapes.) Use the procedure below to restore the
directory. If you have enabled tape drive allocation, use
the MOUNT command instead of the ASSIGN command. (Refer to Section
8.3 for information about using tape drive allocation.)

1. Mount the appropriate tape (in this example, it is on drive
MTA0:)

2. Give the following commands at your terminal.

______ _____
@ENABLE (CAPABILITIES)
______ _____ _____
$ASSIGN (DEVICE) MTA0:
____ _____ _ _____ _____
$SKIP (DEVICE) MTA0: 4 FILES
___ _____ _____
$RUN (PROGRAM) MTA0:

____ _____ _____
DUMPER> TAPE (DEVICE) MTA0:
____ _ _____
DUMPER> SKIP (NUMBER OF SAVESETS) 1
_______ _____________ ________
DUMPER> RESTORE (TAPE FILES) DSK*:<*>*.*.* (TO)
_____

DUMPER TAPE # 1 , , SATURDAY, 3-NOV-88 330
LOADING FILES INTO STR:
END OF SAVESET

____ _____
DUMPER> EXIT
$

3-16
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

3.2.6 and
3.2.6 and

The first time you install the TOPS-20 software, the DLUSER program
creates the directories and . They do not
contain files. You can use these directories when a new release
becomes available and you are updating the existing system. When
DIGITAL distributes an updated monitor on the TOPS-20 Installation
Tape, you restore the first two savesets from this tape to the
directories and respectively. You use these
directories until you feel comfortable with the new software. Should
you have any problems with the new software, you can easily revert to
_______ __ _____ _
using the old software. Appendix A of the TOPS-20 KL Model B
____________ _____
Installation Guide detail the procedures to update one software
release to another.

If you have no problems with the new monitor, and you are comfortable
with it, copy all the files in the directory into the
directory and all the files in the directory
into the directory . You can now delete all the files in
and . The directories and
remain empty until a new version of the TOPS-20 software
is distributed.

NOTE

After you copy the new files into the directories
and , you cannot revert to the old
system software unless you reinstall the system using
the old monitor or backup tapes.

3-17
AFTER SOFTWARE INSTALLATION
AFTER SOFTWARE INSTALLATION

3.2.7 , , , and
3.2.7 , , , and

- After installation, the directory contains one
file, SYSTEM-DATA.BIN. This file contains all the accounting system
entries for each user. If the directory is destroyed, the
accounting system creates a new SYSTEM-DATA.BIN file.

After the first LOGIN on the system, the system creates the
CHECKPOINT.BIN file. This file stores accounting entries
for each user during the time the user is logged in. After a user
logs out, the accounting data stored in CHECKPOINT.BIN is copied to
the SYSTEM-DATA.BIN file. When the system comes up after a crash, the
monitor examines CHECKPOINT.BIN to determine which users
were logged in at the time of the crash, and stores the data in
CHECKPOINT.BIN in SYSTEM-DATA.BIN. Therefore, users who did not log
out in the normal fashion, because of a crash, are still charged for
their log-in time.

- The directory normally contains the file
PTYCON.LOG. This file usually contains a record of all the activities
that occur under the operator jobs that are controlled by PTYCON. The
directory may also contain files the operator needs to run

the system. - The directory contains files that the
spooling system needs before performing any input or output. They are
kept in this area until they can be output to a slow-speed device such
as a line printer. This area is also used for input of files from the
local card reader, if one is attached. It may also be used for input
of files from IBM remote stations. The file
PRIMARY-MASTER-QUEUE-FILE.QUASAR is created in this directory. It
contains a copy of the input queues so that they are not destroyed if
the system crashes. You must either delete this file or process all
entries in the queues before installing a new version of the batch
system that has a different queue format. The GALAXY.DOC file
describes the new software components and tells you if the queue
format has changed.

- The directory contains the file
ERROR.SYS. The ERROR.SYS file contains entries about system errors
and is read by the system error recovery program, SPEAR.

3.2.8 Other Useful Directories
3.2.8 Other Useful Directories

You may want to create additional directories for storing different
versions of programs or text. Some useful directories are listed
below. You should give these directories the proper protection number
and make them files-only directories.

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Directory and File Protection

Directories and files that are executed or read by the entire user
community should not be given the default protection 777700, which
allows no access. They should be given the directory protection
777740 and the file protection 777752 or 777712. (Section 5.7
describes directory and file protections.)

The directory can contain versions of your
software that are not completely tested or that
are drastically different from the current
versions. If you create a directory , users
will find it more convenient if you also create
the system-logical name NEW: defined as
PUB:, SYS:, where PUB: is the system
structure. This logical name allows them to run
all new software by merely typing NEW: and the
program name. If there is no file with the given
name in , the system uses the version
currently on . (Refer to Section 3.3 for
a description of logical names.)

The directory can contain the old version
of software as newer versions appear on .
If programs or data do not work with new
software, the user has a chance to correct the
problems before the older software is no longer
available. Users will find it convenient if you
also define the system-logical name OLD: as
PUB:,SYS:, where PUB: is the system
structure.

By creating the directories and , you gradually introduce
new software to system users. When a new version becomes available,
place it in the directory . When the software has been in use
awhile, move the version in to , and the version in
to . Store the version in on a system back-up
tape. Every time you change a version of the software, you should
send a system-wide message to all users.

The directory contains documents and help
files that describe the system software. As
different versions of software appear on
, , and , you should make a
list of changes incorporated in the new versions
and place it in the directory . You can
move all files with the file type .HLP from
to the directory . The HELP
command still works correctly if you define the
system-logical name HLP: to be PUB:,SYS:,
where PUB: is the system structure.

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The directory contains messages from
users to the operator. These messages are usually
general system comments or complaints. When a
user wants to send the operator a message that
does not require an immediate response, he can
send a message to the directory using
the MAIL program. (Refer to the description of
_______ ____ _________
the MAIL program in the TOPS-20 User Utilities
______
Guide.) A typical message may be a request for
supplies, for example, LA36 paper or ribbon.
Creating the directory avoids constant
interruptions to the operator from users issuing
PLEASE requests. The operator can read the
messages in at a specified time each
day, or simply when he has time.

3.3 SYSTEM-LOGICAL NAMES
3.3 SYSTEM-LOGICAL NAMES

A logical name is a descriptive word used to establish a search route
to locate files. It can be up to 39 alphanumeric characters; however,
it is usually three to six alphanumeric characters. Because logical
names are used in place of device names, they always end with a colon.
Logical names tell the system where and in what order to search for
files. When a user types a logical name, the system searches the
directories in the order they were defined or listed by the logical
name. Although users can define logical names for their own use
_______ ______ _____
(refer to the TOPS-20 User's Guide), the logical names described here
can be used by all users of the system. You can define system-logical
names in the n-CONFIG.CMD file.

During installation, several systemwide logical names are defined by
the monitor, and may be overridden in the n-CONFIG.CMD file. They are
SYS:, defined as PUB:, PUB:; SYSTEM:, defined as
PUB:, PUB:; DEFAULT-EXEC:, defined as
SYSTEM:EXEC.EXE; and POBOX:, defined as the public structure. (PUB:
is the system structure.) You may decide to add other logical names to
aid users in accessing files. If you want the logical names to be
permanent, place the definitions (using an editor) in the
n-CONFIG.CMD file on the system structure.

SYSTEM:, SYS:, DEFAULT-EXEC:, POBOX:, and some other frequently used
system-logical names are explained below.

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3.3.1 SYSTEM:
3.3.1 SYSTEM:

The logical name, SYSTEM:, defines a search list that contains all the
system programs and files that the system needs to operate. SYSTEM:
should always contain the directory on the system structure.
If you are updating the system with a new monitor, the definition of
SYSTEM: in the n-CONFIG.CMD file also contains the directory
. For example,

DEFINE SYSTEM: STR:,STR:

where:

STR: is the name of the system structure.

3.3.2 SYS:
3.3.2 SYS:

The logical name SYS: defines a search list that contains all the
system programs a user may want to run. SYS: should always contain
the directory and any other library directories that contain
commonly used programs. If you are updating the system with a new
monitor, the definition of SYS: in the n-CONFIG.CMD file also
contains the directory . For example,

DEFINE SYS: STR:,STR:

where:

STR: is the name of the system structure.

Be sure to set the protection on the library files in (or
) to 777740. This protection allows access by all users.

3.3.3 NEW:
3.3.3 NEW:

The logical name NEW: defines a search list containing a directory
that has new software, followed by the system-logical name SYS:. The
definition for this, which you would put in n-CONFIG.CMD, is the
following:

DEFINE NEW: STR:,SYS:

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With this systemwide logical name, the user can give the command:

______ ____ ____ _____
@DEFINE (LOGICAL NAME) SYS: (AS) NEW:

Now, when the user runs a program, the system looks first in the
directory STR:, and then in the normal system search list SYS:.
This way, the user always gets the most recent version of any program.

3.3.4 OLD:
3.3.4 OLD:

If you have old versions of programs, defining the system-logical name
OLD: may be helpful to users. The usual definition of the logical
name OLD: is:

DEFINE OLD: STR:,SYS:

The definition OLD: has the same type of effect as the definition
NEW:. If the user gives the command:

______ ____ _________
@DEFINE (LOGICAL NAME) SYS: (AS) OLD:

whenever he runs a program, he will get the oldest version available.

3.3.5 HLP:
3.3.5 HLP:

If you want to keep programs and documentation in separate
directories, you should store the documentation in . The HELP
command searches the directories identified by the logical name HLP:,
so you must define the logical name HLP: to be the directory .

The definition of HLP: in n-CONFIG.CMD should be:

DEFINE HLP: STR:

3.3.6 SERR:
3.3.6 SERR:

The logical name SERR: is defined by the system at startup. It points
to the area on the system structure. The system writes
the ERROR.SYS file to this area, which may be used later to produce
reports.

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3.3.7 DMP:
3.3.7 DMP:

When the system is re-booted after a crash, the file DUMP.EXE is
overwritten with a copy of memory. Upon system startup, the n-SETSPD
program copies the contents of DUMP.EXE to the DUMP-version-name.CPY
file on the system structure (name is the name of the bug, and version
is the edit number of the monitor that was running at the time of the
crash). System crashes cause DUMP.EXE to be overwritten, but new
versions of the .CPY file accumulate. To keep the system structure
clear of .CPY files, define DMP: in the n-CONFIG.CMD file as follows:

DEFINE DMP: STR:

The structure and directory are your choice; you should not specify a
filename. Versions of the .CPY file hereafter accumulate in the
defined area.

___
In CFS configurations, systems should not share a common
DMP: definition, because this could lead to confusion about which dump
came from which system.

If the DUMP-ON-BUGCHK feature is enabled, the n-SETSPD program is run
after continuable system errors, and it copies to DMP: all new
DUMP.EXE files that it finds from its scan of dumpable structures.
Refer to Section 9.10 for complete information on DUMP-ON-BUGCHK.

As n-SETSPD copies a file to the area defined by DMP:, it sends a
message to the CTY specifying where it's copying the file to and from.
For example:

Copying system dump
from: STR:DUMP.EXE.1
to: PS60:DUMP-12345-WSPNEG.CPY.1

3.3.8 DEFAULT-EXEC:
3.3.8 DEFAULT-EXEC:

The logical name DEFAULT-EXEC: defines a search list that points to
the TOPS-20 Command Processor (EXEC). When users log in or give the
PUSH command, the EXEC program is activated. Some experienced users
may choose to run their own copies of the EXEC, not the standard
system version. Such users can define DEFAULT-EXEC: to be the file
name for their private EXEC, and can take advantage of this feature
after giving the PUSH command. This command must be given at the EXEC
level, while in batch or interactive mode. PUSH commands issued from
other program levels may invoke the standard system version, unless
the program has been written to use DEFAULT-EXEC: if it is defined.
By default, DEFAULT-EXEC: is defined as SYSTEM:EXEC.EXE.

____________ _________ _______ _______ ________
Refer to the DECSYSTEM-20 Technical Summary and the TOPS-20 Commands
_________ ______
Reference Manual for more complete information on the EXEC.

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3.3.9 POBOX:
3.3.9 POBOX:

The logical name POBOX: defines a search list that points to
structures where users' mail files reside. Mail sent to a user goes
to the first MAIL.TXT.1 file in the user's directory that the system
encounters in its search.

By default, POBOX: is defined as the public structure. You can
redefine POBOX: in the n-CONFIG.CMD file. By redefining POBOX:, you
can prevent users' mail files from filling up the public structure.

In CFS-20 configurations, redefining POBOX: is especially useful. You
can define POBOX: to be the same structure for all systems,
establishing a central location for all mail files in the
configuration. Then, no matter what system users log onto, they are
automatically directed to this one area when they give commands to
access their mail. They do not have to spend time logging onto
various systems to access mail that would otherwise have been sent to
a public structure (which is a separate structure for each system
unless the "login structure" feature is enabled). To set up this
central location, the same DEFINE command should be entered in each
system's n-CONFIG.CMD file. Refer to Chapter 12, The Common File
System, for further information on CFS-20.

3.3.10 NRT:
3.3.10 NRT:

The logical name NRT: (Network Remote Terminal) is applicable only if
your system has DECnet communications software. When a user issues
the SET HOST command to connect to a remote system, the CTERM-SERVER
communications program is run by default. If the remote node does not
support CTERM, the host system tries to connect the user again, this
time using the program defined by NRT:.

________
Examples

1. For TOPS-20 to TOPS-20 communications, give the following
definition:

DEFINE NRT: SYS:SETHOST.EXE

2. For multi-operating system DECnet communications, you can
specify the HOST program (located on the TOPS-20 tools tape):

DEFINE NRT: HOST.EXE

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3.3.11 SPOOL:
3.3.11 SPOOL:

The logical name SPOOL: directs the system to the directory
on the system structure. The GALAXY batch and spooling components
read and write files in this area. Also, the monitor writes spooled
files to this area. (Section 3.2.7 contains detailed information on
.

3.4 CONSOLE FRONT-END FILES
3.4 CONSOLE FRONT-END FILES

The console front-end computer consists of a PDP-11 with 28K 16-bit
words of memory. When the system is brought up for timesharing, the
front-end monitor, RSX20F, is loaded in the PDP-11 memory and started.
The TOPS-20 monitor is loaded in KL10 main memory and started. Thus,
you have two computers working together. Both computers have their
own monitor and related software.

The front-end file system consists of the RSX20F monitor and related
programs (tasks) and files. During software installation, these
front-end files are transferred from floppy disks to a special area on
the system structure unless an RP07 is being used as the system
structure. If an RP07 is being used as the system structure, only the
files on the TOPS-20 Installation Tape will be placed on the RP07.
The front-end files, on the floppy disks, must be placed on a
dual-ported RP06 disk drive attached to the PDP-11 front end. (Refer
_______ __ _____ _ ____________ _____
to the TOPS-20 KL Model B Installation Guide for the procedure for
creating the front-end file system when using an RP07 disk drive as
the system structure.)

The area the front-end files are placed on is called the FRONT-END
FILES area, or FILES-11 area. Once this area has been set-up, there
is normally no need to get these files again from floppy disks. The
floppy disks used to install the system become backup devices in case
the system structure is destroyed, or in the case where an RP07 is
being used as the system structure, they can be used to recreate your
front-end file structure. It is a good idea to make an extra copy of
your installation floppies in the event one of your original floppies
is destroyed and you need to restore the FRONT-END FILES area. Refer
to Chapter 7, System Backup Procedures, for a description of the COP
program that is used to copy floppy disks.

As previously stated, the front-end files must always be placed on a
dual-ported RP06 attached to the PDP-11 front end. This allows the
front-end processor to access these files while the main processor
accesses TOPS-20 files on the same or different disk packs.

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The RSX20F monitor and its related programs do the following:

o Control input/output and communications devices.

o Interface with the main computer.

o Load the TOPS-20 monitor at system startup, and reload
TOPS-20 if a crash occurs.

o Report system errors to TOPS-20.

o Perform system diagnostic functions.

Table 3-3 lists the programs and files located in the FRONT-END FILES
area, with a brief description of each. Files with the file type TSK
are programs that can be run under the front-end monitor RSX20F; files
with the type MCB contain the microcode for the host processor (KL10);
files with the type EXB are bootstrap programs used to load the
TOPS-20 monitor; and files with the type CMD are programs that record
information about system errors. This information is read by the
system error recovery program, SPEAR. Beginning with TOPS-20 Version
6, console front-end filenames include edit-level numbers that
indicate the versions of the particular programs, for example,
F11ACP.TSK;1505.

Table 3-3: Console Front-End Files
Table 3-3: Console Front-End Files

__________________________________________________________________

File Contents or Function
File Contents or Function
__________________________________________________________________

BF16N1.A11 MOS memory-timing RAM file. It is a nonexecutable
file containing MOS memory data.

BF64N1.A11 Timing file for 64K RAM chips.

BOO.TSK Used to boot RSX20F.

BOOT.EXB The central processor disk bootstrap program that
boots TOPS-20 from disk.

CLOCK.CMD Saves contents of memory locations for diagnosing
errors that are purposely induced by Field
Service.

COP.TSK Copies the contents of floppy disks.

CRAM.CMD Saves contents of memory locations for diagnosing
CRAM parity errors.

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Table 3-3: Console Front-End Files (Cont.)
Table 3-3: Console Front-End Files (Cont.)

File Contents or Function
File Contents or Function

DEX.CMD Saves contents of memory locations for diagnosing
Deposit Examine failures (PI level 0 interrupt).

DMO.TSK Dismounts a front-end device and allows a reboot.

DRAM.CMD Saves contents of memory locations for diagnosing
DRAM parity errors.

EBUS.CMD Saves contents of memory locations for diagnosing
EBUS parity errors.

FMPAR.CMD Saves contents of memory locations for diagnosing
fast memory parity errors.

F11ACP.TSK File handler for front-end disk files.

HALT.CMD Saves contents of memory locations for diagnosing
KL halt errors.

INI.TSK Initializes a front-end files area.

KLDISC.TSK Provides the KLINIK line disconnect service.

KLI.TSK KLINIT program for initializing the central
processor (KL20). Loads microcode, configures
cache and main memory, loads bootstrap.

KLRING.TSK Provides the KLINIK line ring service.

KLX.MCB KL10 microcode file.

KPALV.CMD Saves contents of memory locations for diagnosing
keep alive cease errors.

LHALT.CMD Saves contents of memory locations for diagnosing
KL halt errors. Provides more information than
HALT.CMD

LOGXFR.TSK Transfers the PARSER.LOG file to the TOPS-20
error file.

MIDNIT.TSK Updates the time of day through midnight.

MOU.TSK Mounts a device for use with the front end.

MTBOOT.EXB Boots a TOPS-20 monitor from magnetic tape.

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Table 3-3: Console Front-End Files (Cont.)
Table 3-3: Console Front-End Files (Cont.)

File Contents or Function
File Contents or Function

PARSER.TSK The front-end command parser (prompts PAR>). The
primary means of access to front-end programs.

PIP.TSK Front-end program for file transfer.

RED.TSK Tells the system where to look for the front-end
files device, SY0:.

RP2DBT.EXB A front-end BOOT file with the DX20 microcode
loaded for the RP20 disk sybsystem.

RP2MBT.EXB A front-end MTBOOT file with the DX20 microcode
loaded for the RP20 disk sybsystem.

RSX20F.MAP Contains symbolic definitions for RSX20F.

RSX20F.SYS Virgin image of front-end monitor (RSX20F).

SAV.TSK Saves the front-end monitor and bootstrap on
disk.

SETSPD.TSK Sets system parameters, such as line speeds.

TIMEO.CMD Saves contents of memory locations for diagnosing
protocol timeout errors.

TKTN.TSK Terminates tasks, reports errors, and requests
reloads.

T20ACP.TSK Interfaces between front-end and TOPS-20 file
systems.

UFD.TSK Sets up user-file directories in the front-end
files area.

ZAP.TSK Makes binary modifications to task images.
__________________________________________________________________

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3.5 TAILORING THE BATCH SYSTEM
3.5 TAILORING THE BATCH SYSTEM

Most installations use the parameters and defaults in the distributed
version of the batch system. However, you can modify some of these
parameters if required by the batch processing procedures at your
installation.

DIGITAL distributes a program with the TOPS-20 software that allows
you to tailor the standard batch system to the requirements of your
installation. This program, called GALGEN.EXE, is located in the
directory on the system structure. You can run GALGEN at the
time the system software is installed or at a later date. In either
case, you must have a working batch system before you can generate a
new one using GALGEN. This means if you are installing the system,
you must first install the batch system that is distributed with every
new version of the TOPS-20 software (on the software installation
tape). You can then run the GALGEN program and tailor the batch
system before it becomes available for general use.

If you tailor the batch system at a later date, you can run the GALGEN
program with users logged in. However, for safety reasons, the system
should be stand-alone during the critical phase of stopping the old
batch system and starting the new one. The batch queues, however,
need not be empty. That is, batch jobs can be waiting to be processed
at the time you bring the system down.

_______ __ _____ _ ____________ _____
The TOPS-20 KL Model B Installation Guide contains the procedures for
running the GALGEN program.

3.6 CHECKING THE SOFTWARE (UETP)
3.6 CHECKING THE SOFTWARE (UETP)

After the system software is installed, you or the Software Specialist
can run the User Environment Test Package (UETP). UETP is a
collection of programs, data files, and batch control files designed
to allow you to test the integrity of various system elements. In
addition to testing that the hardware has been properly installed,
UETP ensures that the TOPS-20 Operating System is running and that the
languages you have selected for your operation are available.

UETP creates a moderate load on the system, consisting of various
defined procedures that closely resemble the load in an actual
operation. Later, you may want to tailor UETP to test a software load
that more closely resembles your particular system's use.

_______________ ____ ___________ ____ _______ _________ ______
The TOPS-10/TOPS-20 User Environment Test Package Reference Manual
describes UETP, the individual component tests, typical message
information, and the procedures for adding new tests.

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3.7 REMOTE PRINTERS
3.7 REMOTE PRINTERS

The DECSYSTEM-20s at your site may be included in a DECnet network,
local area network, or CFS-20 cluster. These networks provide TOPS-20
users with numerous printing options. Users, not restricted to local
printers on the systems they logged in to, can direct output to remote
printers attached to:

o VMS systems in a DECnet network -- Distributed Queue Service
(DQS) printers.

o LAT servers in a local area network -- LAT printers.

o Other TOPS-20 systems in a CFS-20 cluster -- cluster
printers.

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3.7.1 Remote Printing Requirements
3.7.1 Remote Printing Requirements

___
o Use of DQS printers requires DECnet.

___ ________
o Use of LAT printers requires a LAT server running at least
Version 5.1 of the LAT protocol. Digital-supported LAT
printers must be one of the following devices: LA50, LA75,
LA100, LA120, LN03.

When starting up a LAT printer, the operator must enter a
description for the printer with the
/TERMINAL-CHARACTERISTIC: switch to the OPR>START PRINTER
command. (If the switch is omitted, the system prompts the
operator for this information.) You or a system programmer
must establish values for the switch argument in the LPTSPL
module, LPTUSR.MAC. Instructions for doing this are included
in the GALAXY documentation file.

_______ _______
o Use of a remote cluster printer requires DECnet.

In addition, "cluster GALAXY" must be enabled on both the
requesting and serving systems if users are to have access to
the full set of remote-printer functions. These functions
include: obtaining information on remote print queues,
canceling remote print requests, and receiving notification
of queuing and completing of the remote print job.

A system that is servicing remote cluster print jobs must run
LPTSPL and LISSPL.

A system that is sending print jobs to a system that services
them must run LPTSPL. A cluster printer must be started on
this system also. For example, if system SYSA sends print
requests to system SYSB, the operator gives the following
command from SYSA:

_____ _______ _______ ____ ______ ____ _________
OPR>START PRINTER CLUSTER unit number NODE SYSB

where:

unit number designates a printer at SYSB

_______ __ _____ _ ____________ _____
Refer to the TOPS-20 KL Model B Installation Guide and the
_______ __________ _____
TOPS-20 Operator's Guide for further information on
installing and enabling cluster printing.

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3.7.2 Defining DQS and LAT Printers
3.7.2 Defining DQS and LAT Printers

To specify a DQS or LAT printer with the PRINT/REMOTE-PRINTER:
command, users must first define that printer with the SET
REMOTE-PRINTING PRINTER command, which indicates where the printer
resides in the network. It can provide a useful alias for the printer
as well. Users can issue the command interactively at the terminal or
from a jobwide command file.

More conveniently, however, users can invoke the command for each
available printer from a systemwide command file that you create. You
should name this file REMOTE-PRINTING.CMD and place it in the SYSTEM:
area. Users can invoke the commands in this file with the TAKE
command or the SET REMOTE-PRINTING SYSTEM-DEFINITIONS command. (You
can also place these commands in COMAND.CMD if all users on a
system are expected to want to use this facility.) Here is a sample
systemwide printer-definition file:

SET REMOTE-PRINTING PRINTER LN03 SWE$LN03 SYSA
SET REMOTE-PRINTING PRINTER LISTING SI$8700 SYSB
SET REMOTE-PRINTING PRINTER LATOP LC14 LAT99

The SET REMOTE-PRINTING PRINTER command has three arguments. The
first argument assigns an alias to the remote printer. The second
argument is the name of a VMS printer queue (SWE$LN03) or a LAT port
or service (LC14) or the name of an existing alias (SET
REMOTE-PRINTING PRINTER LAT03 LN03). The third argument is the name
of the system or LAT server that controls the printer.

_______ ________ _________ ______
Refer to the TOPS-20 Commands Reference Manual for a complete
description of the command.

The REMOTE-PRINTING.CMD file can also contain specifications for DQS
printing characteristics, as described in section 3.7.3.

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3.7.3 Setting DQS Printing Characteristics
3.7.3 Setting DQS Printing Characteristics

Users can specify how they want their DQS printed output to appear.
For example, they may desire a "landscape" or "portrait" page
orientation, or 65 or 90 characters per line. They can specify these
and other characteristics with the PRINT/CHARACTERISTICS command.
However, the printing characteristics must first be established with
the SET REMOTE-PRINTING CHARACTERISTIC command. Like the printer
definitions described in Section 3.7.2, the printing characteristics
can be established by invoking the appropriate command from the
terminal, a jobwide command file, or the systemwide command file,
SYSTEM:REMOTE-PRINTING.CMD.

Here is a systemwide command file that contains printing
characteristics and printer definitions:

SET REMOTE-PRINTING PRINTER LISTING SI$8700 SYSA
SET REMOTE-PRINTING PRINTER LN03 CS$LN03 SYSB
SET REMOTE-PRINTING PRINTER LATOP LC14 LAT99

The SET REMOTE-PRINTING CHARACTERISTIC command has two arguments. The
first argument is the name of a characteristic, for example, PORTRAIT,
or P90 (portrait orientation with 90 characters per line). The second
argument is the numeric value that your site has assigned to that
characteristic for the particular printer queue or to the name of an
existing characteristic.

You can also place this command in the COMAND.CMD file if all
users on a system are expected to want to use this facility.

_______ ________ _________ ______
Refer to the TOPS-20 Commands Reference Manual for a complete
description of the command.

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3.8 TERMINAL PRINTERS
3.8 TERMINAL PRINTERS

Your site may have printers attached to dedicated, hardwired terminal
lines, such as an LA50, LA100, LA120-RA, or LA120-RB. These local
printers are called terminal printers. The operator starts them with
the following command:

_____ _______ ______________________________________________
OPR>START PRINTER unit/DEVICE:TTYn/TERMINAL-CHARACTERISTIC:

where:

unit is the number that designates a printer

n is the terminal line number

You or a system programmer must assign a descriptive value to each of
these printers in the LPTSPL module, LPTUSR.MAC. Instructions for
doing this are included in the GALAXY documentation file. The
argument that the operator gives to the /TERMINAL-CHARACTERISTIC:
switch with the OPR>START PRINTER command must match a value in
LPTUSR.MAC.

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CHAPTER 4
CHAPTER 4

CREATING STRUCTURES
CREATING STRUCTURES

4.1 OVERVIEW
4.1 OVERVIEW

One of the first decisions you must make about your new (or upgraded)
installation is what type of disk storage environment best suits your
needs. Some of the considerations that determine your decision are:

o How large will the data base be?

o How many users will be using the system?

o How experienced will these users be?

o Will there be a full-time operator?

o How often will you run diagnostics and how critical is it
that the system remain available during this maintenance?

o Must all files be available to all users at all times during
system operation?

o Are multiple systems part of a CFS configuration? Refer also
to Chapter 12, The Common File System.

The mountable structure facility of TOPS-20 provides several options
for making this decision. The option you choose depends on the
answers to the previous questions and the number of disk packs and
drives that are available. For example, if your installation has a
number of disk packs and two or more drives, you can store data and
program files on different structures.

A structure is a collection of data and program files contained on one
or more disk packs and referenced under one name.

When you install your software, you create a structure known as the
system structure (sometimes called the boot structure). All packs in
this structure remain on-line at all times during system operation.
If your system structure does not encompass all of your available
drives you can create and mount other structures.

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Sections 4.2 through 4.8 describe the system structure and how you can
best utilize your disk resources and create and use other structures.

4.2 THE SYSTEM STRUCTURE
4.2 THE SYSTEM STRUCTURE

Sections 4.2.1 and 4.2.2 provide an overview of what the system
structure is, including its relationship to the system and its
contents.

NOTE

Unless you have enabled the "login structure" feature
in a CFS-20 configuration, described in Section
12.6.2, the public, system, boot, and login structures
all denote the same structure.

4.2.1 What Is the System Structure?
4.2.1 What Is the System Structure?

The system structure is the most important structure on your system.
It is created and brought on-line at system installation when you
answer the appropriate questions in the installation dialog. (Refer
_______ __ _____ _ ____________ _____
to the TOPS-20 KL Model B Installation Guide.) The name of the system
structure can be up to six characters.

The system structure can be one or more disk packs, depending on the
configuration of your system and your disk drive resources. You may
use one or more RP06 or RP07 disks as the system structure; the
maximum number of disks per structure is given in Table 4-4. You may
NOT use an RA60, RA81, or RP20 as the system structure.

While installing the software, you copy the console front-end files to
the system structure pack that is mounted on a dual-ported drive
(usually drive 0). The dual port allows the front-end processor and
the central processor to access the data on the system structure.
However, if you are using an RP07 as the system structure, you must
reserve space for the front-end files on an RP06 disk that is
dual-ported to the PDP-11 front end. If the disk structure containing
the front-end files has multiple packs, the first pack of the
structure must be permanently mounted on the dual-ported drive.

All disk packs in the system structure must be online at all times,
because this structure contains all the programs, files, and swapping
area that the system needs to operate. The structure also contains
all user directories necessary to support users logging into the
system. (If the "login structure" feature is enabled in a CFS-20
configuration, the login structure contains these directories and must
also be online at all times.) If the file system is destroyed on the
system structure, or if a drive that contains all or part of the
structure malfunctions, the system halts. Refer to Chapter 9 in this

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_______ __________ _____
manual and to the TOPS-20 Operator's Guide for the steps that you and
the operator must follow if you have problems with the file system or
if a drive goes down.

You can have another structure online that is capable of being used as
the system structure. This structure must have a unique name,
however, at least while it is mounted. (Section 4.5.2 provides
information about mounting structures having the same name.) Section
4.5.5 discusses why you would have such a structure.

| If you include the ENABLE JOB0-CTY-OUTPUT command in the n-CONFIG.CMD
| file, the operator is notified at the console terminal when disk space
| becomes low on the system structure.

If you are using CFS-20 software, refer to Chapter 12, The Common File
System, for additional information on the system structure.

4.2.2 The Contents of the System Structure
4.2.2 The Contents of the System Structure

The following list provides an overview of the contents of the system
structure:

1. The default TOPS-20 command processor, EXEC, which is usually
found in or .

2. A (Section 3.2.1) that points to the
location on disk of all first-level directories on the system
structure, including the special system directories.

3. All the files in the directories and
(Sections 3.2.2 and 3.2.4).

4. The directories , , ,
, and (Sections 3.2.6 and
3.2.7).

5. The front-end monitor (RSX20F) and the console front-end
files (Section 3.4). This normally appears in the
. If you are using the RP07 as the system
structure, the front-end file system must reside on an RP06
dual-ported disk drive.

6. The required swapping area. The size of this area depends on
the TOPS-20 monitor you are using. For example, 2060-MONMAX
uses up to 15,000 pages of disk space for swapping. (Refer
to Section 4.7 for a description of the swapping area.)

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7. A HOME block that contains the following parameters:

o the structure's physical name

o the number of disk packs in the structure

o which pack this is in the structure

o the address and number of pages used for the front-end
file system (usually 950)

o the address and number of pages set aside for swapping

o the address of the and its backup copy

o the serial number of the KL CPU to be booted from the
structure

8. A directory for every user who requires access to the system.
Users must log into a directory on the system structure to
use the system. Afterwards, they can mount and connect to a
different structure and directory. (If the "login structure"
is enabled, CFS-20 users log in to the designated public
structure.)

4.3 ONE-STRUCTURE SYSTEMS
4.3 ONE-STRUCTURE SYSTEMS

A one-structure system consists of a single structure, the system
structure, which is always on-line. All packs in the structure must
be on-line for the system to operate.

Usually, a one-structure system has only one or two disk drives.
Smaller TOPS-20 installations choose to keep all their directories and
files on one structure for some of the following reasons:

o It is the simplest system.

o It is the easiest system to maintain.

o There is no requirement to physically remove packs from the
drives, for example, for security reasons.

o The majority of users are inexperienced.

o All files are available at all times, and thus are easy to
access.

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o A full-time operator may be unnecessary.

o There is only one disk drive (only one structure supported).

Chapter 5 describes the methods you can use to create and maintain
directories on your one-structure system.

4.4 MOUNTABLE STRUCTURES
4.4 MOUNTABLE STRUCTURES

If the system structure does not encompass all available disk drives,
you can create and mount other structures on the unused drives. These
"mountable" structures are created using the CHECKD program. The
_______ __________ _____
TOPS-20 Operator's Guide describes creating structures with CHECKD.

NOTE

The system structure is the only structure created at
installation time. All other structures are created
(using the CHECKD program) and brought on-line during
system operation.

4.4.1 Differences Between Mountable and System Structures
4.4.1 Differences Between Mountable and System Structures

Unlike the system structure, a mountable structure can be mounted and
dismounted during timesharing. Also, it need not contain a front-end
file system. Therefore, a mountable structure does not have to reside
on a dual-ported disk drive. Although a mountable structure has its
own and directory system, a user cannot log into a
mountable structure, but must log in as a user on the system
structure. A user can then mount a different structure and connect to
directories. Table 4-1 summarizes the differences between a mountable
and system structure.

4.4.2 Similarities Between Mountable and System Structures
4.4.2 Similarities Between Mountable and System Structures

There are, however, many similarities between the system structure and
mountable structures. Both contain user directories and files. A
mountable structure can have a front-end file system, and can be used
in place of the system structure to load the system for timesharing.
A mountable structure is created with the eight special directories
(mentioned in Chapter 3) as for a system structure. Likewise, a
mountable structure has a HOME block that contains information such as
the name of the structure and the number of disk units in the
structure. These and other similarities are summarized in Table 4-2.

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Table 4-1: Differences Between Mountable and System Structures
Table 4-1: Differences Between Mountable and System Structures

__________________________________________________________________

System Structure Mountable Structures
System Structure Mountable Structures
__________________________________________________________________

Always up during timesharing Can be mounted and dismounted

Has a front-end file system Need not have a front-end file
(unless an RP07) system

Resides on a drive that is dual Need not reside on a
ported with the front-end dual-ported disk drive
computer (unless an RP07)

Used for logging into the Cannot be used for logging into
system the system

Belongs to the system Can belong to a private user

Has the , , Need not have these directories
, , unless the structure will be
, and used as the public structure;
directories can be deleted from the
structure

Must contain a swapping area Need not contain a swapping
area unless the structure is to
be mounted as the public
structure
__________________________________________________________________

Table 4-2: Similarities Between Mountable and System Structures
Table 4-2: Similarities Between Mountable and System Structures

__________________________________________________________________

System Structure Mountable Structures
System Structure Mountable Structures
__________________________________________________________________

Has a HOME block Has a HOME block

Has a front-end files area Can have a front-end files area
(unless an RP07)

Is used to load the system Can be used to load the system
if the proper file areas and
files have been established

Contains system files May contain system files

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System Structure Mountable Structures
System Structure Mountable Structures

Has a Has a

Contains user files Contains user files

All packs must be on-line for All packs in the structure must
the system to operate be on-line to use the structure
__________________________________________________________________

4.5 MULTIPLE-STRUCTURE SYSTEMS
4.5 MULTIPLE-STRUCTURE SYSTEMS

A multiple-structure system consists of a system structure and one
or more additional structures. Figure 4-1 illustrates a system with
three disk drives and two structures. The two-pack system structure
MASTER: must be online during timesharing. The one-pack mountable
structure ADMIN: can be removed during timesharing. Another
one-pack structure can be mounted in its place.

UNIT 0 UNIT 1 UNIT 2
______ ______ ______
| | | | | |
| | | | | |
| | | | | |
| | | | | |
| | | | | |
|______| |______| |______|

STRUCTURE MASTER: STRUCTURE ADMIN:

Figure 4-1: System with 3 Disk Drives and 2 Structures
Figure 4-1: System with 3 Disk Drives and 2 Structures

Using Figure 4-1, suppose you want structure ADMIN: to remain
on-line at all times during system operation. The structure is
automatically mounted if you turn on the drive that contains the
_______ __________
structure before the system is brought up. The TOPS-20 Operator's
_____
Guide describes mounting structures automatically.

In addition to the system structure and perhaps another permanent
on-line structure, you may choose to keep one or more disk drives
available for users to mount and dismount "private" packs during
timesharing.

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Figure 4-2 illustrates a system with three disk drives and three
one-pack structures, the system structure MASTER:, ADMIN:, and
PROG:.

UNIT 0 UNIT 1 UNIT 2
______ ______ ______
| | | | | |
| | | | | |
| | | | | |
| | | | | |
| | | | | |
|______| |______| |______|

STRUCTURE STRUCTURE STRUCTURE
MASTER: ADMIN: PROG:

Figure 4-2: Three-Structure System
Figure 4-2: Three-Structure System

In this example, MASTER: contains all the directories necessary to
support log-ins. ADMIN: contains the same, a superset, or a subset
of the same directories as those on MASTER: and remains online at
all times during system operation. The drive that contains PROG:
is used for short-term mounting of different one-pack structures.
PROG: remains online only for the time it is needed.

There can be up to 64 structures online at one time.

Several of the advantages in a mountable structure environment are:

o Some users or groups of users may require a structure
exclusively for their use. They can 'own' or possibly pay
for the use of certain structures.

o Service engineers can mount their own pack on the
short-term drive and perform some diagnostics without
disturbing normal system operation.

o Creating structures on mountable packs provides additional
security to that already within the system. For example,
you can create a structure that contains highly
confidential data, remove it from the drive(s) when you are
done with it, and lock it in a security cabinet or safe.
At the end of the day, the operator locks up any
confidential structures.

o In this type of environment, you are not limited in the
size of your system's data base. You can create as many
structures as you have disk packs to contain them, and you
can mount as many at one time as your system can support.

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The principal disadvantages of using mountable structures are the
need for scheduling both access to the data and operator coverage to
install and remove packs on the drives, as described in Section
1.2.2, Mountable Structure Sign-Up Log. There is also some risk
that packs will be damaged during handling.

After the system is operating and structures have been created, the
operator responds to requests from users to mount and dismount
structures. Section 4.5.5 describes how to place user directories
on your mountable structures to obtain maximum availability to
priority jobs.

4.5.1 Choosing Structure Names
4.5.1 Choosing Structure Names

Each device on the system has a name, called the physical device
name, which is used when giving commands to the software. Unlike
the generic device name that applies to a class of devices, for
example: TTY:, DSK:, LPT:, the physical device name applies to a
particular device on the system; for example, TTY6: and LPT0:. The
physical device names for disks are structure names. A structure
name can be from one to six alphanumeric characters of your choice,
and, like other device names, must be followed by a colon. The
colon indicates to the software that a device is being used and not,
for example, a file.

It is important to carefully assign a unique name to each structure
that you create. Section 4.5.2, Mounting Structures Having the Same
Name, explains why this precaution avoids confusion for users if an
operator is unavailable during timesharing.

Because structure names are used in the device field (dev:) of a
file specification, you should not create any structures with the
same name as a defined (or valid) device name. Table 4-3 lists
device names that may be defined in your system.

For the same reason, avoid naming a structure with a defined logical
name, for example, SYS:, SYSTEM:, NEW:, OLD:, HLP:, etc., because
the system searches the list of defined systemwide logical names
before device names. (Refer to Section 3.3 for a description of
logical names.)

Refer to Chapter 12, The Common File System, for structure-naming
considerations in a CFS environment.

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Table 4-3: Sample Device Names
Table 4-3: Sample Device Names

__________________________________________________________________

DSK: CDP:

MTAn: FEn:

MTn: TTY:

LPT: TTYn:

LPTn: PTYn:

PLPTn: NUL:

CDR: PLT:

PCDRn: PLTn:

PCDPn: DCN:

TCP: SRV:

Where n is the unit number of the device.
__________________________________________________________________

To avoid duplication, you can get a list of all structure names known
to the system by giving the operator command, SHOW STATUS STRUCTURE.
These structures do not have to be online. Their presence in the
listing indicates that they were previously specified in a SET
STRUCTURE command, or once mounted on the system.

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4.5.2 Mounting Structures Having the Same Name
4.5.2 Mounting Structures Having the Same Name

A situation may arise requiring you to mount a structure that has the
same name as a structure that is already online. Perhaps another
installation has requested that you mount its system structure (named
SYSA:) for testing purposes, but you already have a structure named
SYSA: online. Because the system notices ambiguous structure names,
you must mount the structure under a different name.

Each structure that is mounted is identified with two names: the
physical identification and the alias. Usually, these names are the
same. The physical identification is the actual structure name
written in the HOME block of that structure. The alias is the name
that you use to reference the structure while it is mounted. After a
structure is mounted,it is known only by its alias. The MOUNT command
is used to mount a structure and give it an alias different from the
physical identification. This allows two or more structures with the
same physical name to be mounted simultaneously. The system
_______
distinguishes them by their different aliases. (The TOPS-20
__________ _____
Operator's Guide describes this procedure.)

Note that the structures must be mounted one at a time. That is,
structures cannot be online simultaneously before the MOUNT command is
given. One of the structues must be mounted first. It may be
necessary to power down disk drives and bring them up again.

4.5.3 Maximum Size of Structures
4.5.3 Maximum Size of Structures

The maximum size of a structure is approximately 805,680 pages. A
structure of this size requires 3 RP20 disk drives (5 spindles).

Structures of the maximum size, however, may not be practical for your
installation. Smaller structures enhance the reliability and
availability of the system. Remember that you can have up to 64
structures on-line at one time.

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Also, if a structure is contained on more than one disk pack, the
packs and drive units for that structure must all be the same type,
that is, either all RP06s, RP07s, RP20s, RA60s, or RA81s. For
example,

NOT SUPPORTED SUPPORTED
______ ______ ______ ______
| | | | | | | |
| | | | | | | |
| RP06 | | RP07 | | RP07 | | RP07 |
| | | | | | | |
| | | | | | | |
|______| |______| |______| |______|

STRUCTURE ADMIN: STRUCTURE ADMIN:

Table 4-4 shows the maximum structure size using RP06, RP07, RP20,
RA60, and RA81 disk drives. For all drive types, there can be 12,000
directories per structure and 5,000 files per directory.

NOTE

The number of directories per structure and files per
directory that can be created is approximate. This is
because the disk space needed to create a directory or
file varies according to the lengths of the names
chosen for directories and files.

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Table 4-4: Maximum Size Structures
Table 4-4: Maximum Size Structures

__________________________________________________________________

Type of Max.No.Packs No. Pages
Type of Max.No.Packs No. Pages
Disk Drive Per Structure Per Pack
Disk Drive Per Structure Per Pack
__________________________________________________________________

RP04 6 38000

RP06 3 76000

RP07 1 216376

RP20 5 201420

RA60 6 90516

RA81 5 200928
__________________________________________________________________

4.5.4 Increasing the Size of Structures
4.5.4 Increasing the Size of Structures

You can add more disk packs to increase the size of a mountable
structure (not the system structure) during timesharing. To do this,
you must:

o Dump the entire file structure onto magnetic tape using the
DUMPER program

o Run the CHECKD program, specifying the new configuration, to
re-create the structure

o Restore all the directories and files from magnetic tape
using the DUMPER program

IMPORTANT

If possible, re-create the structure and restore the
files to a different set of packs from the structure
that you dumped. This precaution ensures that you do
not lose any valuable data should you have problems
reading the tape back to disk. That is, you still
have the original structure intact and can rerun
DUMPER and copy the structure to another tape.

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To increase the size of the system structure, you must shut down the
system and follow the installation procedure for bringing up this
structure with more disk packs. Refer to Chapter 9, System
_______ __ _____ _ ____________ _____
Problems/Crashes, and to the TOPS-20 KL Model B Installation Guide.

4.5.5 Setting Up Structures for Maximum Availability
4.5.5 Setting Up Structures for Maximum Availability

Before you create structures and place user directories on them, you
should determine which users must be on the system at all times.
Place these users' directories and files on the system structure, or
on another structure that is always available during timesharing.
Divide the remaining users of the system by priority, and place their
directories and files on the other structures. Although these users
have log-in directories on the system structure, their large working
area where they create and store files is on the other on-line
structures. You may want to help users set up their LOGIN.CMD and
BATCH.CMD files so that they can mount, connect, and access the
appropriate directory on the structure where their files are located,
if it is not the system structure. Dividing users into categories and
placing them on structures accordingly ensures that the failure of one
disk drive does not prevent the most important users from using the
system. For example, if the drive that contains ADMIN: goes down,
you can remove the ADMIN: pack from the broken drive, and mount it on
another drive that contains a less critical structure.

Also, on-line disk diagnostics can be performed during timesharing.
Sometimes, the service engineer can dismount a non-critical structure,
mount the maintenance pack, and perform preventive maintenance or
trouble-shooting with only a portion of the user community off-line.

To increase system availability, you can create another system
structure for backup using the CHECKD program. After you create this
structure, you should follow the procedures in your software
installation manual for creating the front-end files area. The
_______ __________ _____
TOPS-20 Operator's Guide describes using the CHECKD program to create
a backup system structure. If you have problems with the primary
system structure, having a second system structure available allows
you to resume timesharing without reinstalling the system.

The backup system structure can be mounted and online at all times
under another name, or it can be kept in storage and mounted as a
backup if the regular system structure is destroyed. If the backup
system structure is kept in storage, the operator must update the
structure periodically with the System Backup Tape and the latest
incremental dumper tapes. (Chapter 7, System Backup, describes
creating and using your System Backup Tape and incremental tapes.)
Occasionally updating your backup system structure (in storage) keeps
it reasonably up-to-date.

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If you keep your backup system structure online at all times, and you
have important files that are constantly accessed by the user
community, you can improve your system performance by placing these
files on the backup system structure. Now your swapping area and the
files that you access frequently are not on the same disk. This
procedure is useful with any structure that you keep on-line at all
times.

If multiple systems are part of a CFS configuration, refer to Chapter
12, The Common File System, for further discussion of placement of
files and user directories.

4.5.6 Taking Structures Off-Line
4.5.6 Taking Structures Off-Line

When a structure must be taken off-line, the operator should notify
users that it will be dismounted at a certain time. Users should give
the DISMOUNT command for the structure before the specified time. If
the users do not cooperate, the operator can dismount the structure
(via the DISMOUNT command to OPR) without leaving files in an unknown
state. Files that are open simply become inaccessible, and the user
who had the files open receives an error.

For information on dismounting structures in a CFS environment, refer
to Chapter 12, The Common File System.

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4.5.7 Mounting Structures from Another Installation
4.5.7 Mounting Structures from Another Installation

If you mount a structure from another installation, or perhaps a
structure that contains confidential data, some of the user names on
this structure may match the user names on your system structure. You
must mount this structure in what is called a FOREIGN state, to avoid
the mishap of your users accessing directories that do not belong to
them. The same is true if you bring one of your structures to another
installation. You should have the operator at the installation SET
the structure FOREIGN and then mount it. Figure 4-3 illustrates this
concept.

_________________________________
| |
| YOUR INSTALLATION |
| |
| _________ _________ | _________
| | | | | | | |
| | | | | __| | |
| | SYSTEM | | PROG: | <----------| FOREIGN |
| | STR: | | | __ | STR: |
| | | | | | | |
| |_________| |_________| | |_________|
| |
| |
| DOMESTIC |
|_________________________________|

Figure 4-3: Domestic and Foreign Structures
Figure 4-3: Domestic and Foreign Structures

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A structure is brought online in one of two states, DOMESTIC or
FOREIGN, according to the setting that the operator last specified for
this structure with the SET STRUCTURE command. The system uses the
FOREIGN state as the default if a SET STRUCTURE command has never been
given for this structure. The structure remains in the specified
state until the operator changes the state with the SET STRUCTURE or
the UNDEFINE command. Note that the setting is unchanged across
system crashes and reloads.

You should bring a structure online as DOMESTIC only if the
directories on that structure were created for the same people as
those on the system structure. One can be a subset of the other, but
a given directory name should represent the same person on both.
Conversely, you should bring a structure on-line as FOREIGN if the
directories on that structure were not necessarily created for the
same people as those on the system structure. This is because a user
who is logged into a directory on the system structure is the owner of
an identically named directory on a DOMESTIC structure, and can give
the CONNECT or ACCESS command to that directory without giving a
password (provided the directory protection allows this type of access
for the owner, which is the usual case). However, a user who logs
into the system structure and gives the CONNECT or ACCESS command to a
directory with an identical name on a FOREIGN structure must give the
associated password.

4.6 SHARING STRUCTURES (DISK DRIVES) BETWEEN TWO SYSTEMS
4.6 SHARING STRUCTURES (DISK DRIVES) BETWEEN TWO SYSTEMS

If you have two DECSYSTEM-20s and one or more structures that contain
data common to both of these systems, you may want to set up your
system to share disk drives alternately. For example, you could allow
System A to use the drive that contains structure ADMIN: in the
morning and allow System B to use this structure on the same drive in
___ _______ _______ ________ ______ ___ _____ __ ___
the afternoon. THE SYSTEMS CANNOT, HOWEVER, ACCESS THE DRIVE AT THE
____ ____
SAME TIME. (Refer to Chapter 12, The Common File System, for the
exception.) Also, if one of your systems goes down, you can still use
the drive that is connected to both systems.

A drive that is to be shared by two systems must be supported by both
systems. For example, you cannot connect an RM03 disk drive to a
DECSYSTEM-2020 and a DECSYSTEM-2065 because the 2065 system does not
support RM03s. Also, the shared drive must be dual-ported. Your
field service representative must make the appropriate connections
from each DECSYSTEM-20 to a port on the disk drive. Be sure to have
the field service representative tell you which system is connected to
which port on the drive. Figure 4-4 illustrates this connection.

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______________
/ /|
/_____________/ |
| | |
---------- A --->| Dual-Ported | |<--- B ----------------------
| | DRIVE | | |
| |_____________|/ |
| |
| ______________ ______________ |
| | | | | |
------| DECSYSTEM-20 | | DECSYSTEM-20 |-----
|______________| |______________|
| |
| |
_____|_____ _____|_____
| | | |
| FRONT-END | | FRONT-END |
|___________| |___________|

Figure 4-4: Shared Disk Drive
Figure 4-4: Shared Disk Drive

The port switch on this drive must be in either the A or B position,
unless the systems are part of a CFS configuration. Otherwise,
TOPS-20 will not permit either system to access the disk while it is
in the A/B position. Error messages will be generated.

To use the drive, place the port switch in the position that
corresponds to the first system that is using the drive (A or B). The
operator mounts a structure using the normal procedure. After the
first system is no longer allowed to use the drive, the operator gives
the DISMOUNT command for the structure.

To use the drive on the second system, the operator leaves the pack on
the drive (if you are using the same structure), turns the drive
off-line, changes the port switch to the corresponding system, and
turns the drive back on. Then, the operator (or a user) gives the
MOUNT command to mount the structure on this system. The system
automatically recognizes that another drive is on-line and mounts the
structure.

4-18
CREATING STRUCTURES
CREATING STRUCTURES

4.7 DETERMINING SWAPPING SPACE ON THE SYSTEM STRUCTURE
4.7 DETERMINING SWAPPING SPACE ON THE SYSTEM STRUCTURE

Sections 4.7.1 and 4.7.2 describe what swapping space is and how to
determine the amount of swapping space that you should allocate for
your system.

4.7.1 What Is Swapping?
4.7.1 What Is Swapping?

The number of user processes that can fit into main memory
simultaneously depends on the size of the individual processes, the
size of the memory-resident portion of the monitor, and the size of
memory physically available. (Only a portion of the TOPS-20 monitor
resides in main memory at one time.) If a user wishes to run a process
that is not currently in memory, process space must be provided. This
may necessitate moving some other process out of memory. The user's
program or data that is transferred out of memory is placed on disk in
the swapping area. The system sets aside a portion of the disk
storage space on the system structure specifically for this purpose.

On some timesharing systems, a program must be entirely in main memory
to execute. Swapping then consists of moving entire programs between
disk and memory. Under TOPS-20, only portions of a program (those
containing the instructions and data currently being referenced) need
be in memory. Other portions of the program are brought into memory
from disk as they are needed. In this case, swapping consists of
moving portions of a program or data between disk and memory. The
monitor decides which portions of which programs to swap, and when.

The size of a program is measured in a unit called a page. When
swapping occurs, some of these pages are copied between memory and
disk.

4.7.2 When to Increase Swapping Space
4.7.2 When to Increase Swapping Space

For the most part, the size of your swapping space depends on the
cumulative size of processes you estimate will be on the system at any
one time. Table 4-5 contains guidelines for estimating the amount of
swapping space required for an approximate number of user jobs based
on typical requirements. This amount is given in response to the
question, "HOW MANY PAGES FOR SWAPPING?" in the software installation
procedures.

The actual disk space used for swapping depends on the number of pages
you give. The system rounds the number of pages given upward to an
integral number of cylinders. The swapping space is divided equally
among the disk packs in the system structure.

4-19
CREATING STRUCTURES
CREATING STRUCTURES

You can allow for swapping space on structures other than the system
structure. However, this is necessary only if you plan to mount the
structure as the system structure in the future. Allocating swapping
space avoids re-creating the structure should you decide to mount it
as the system structure.

All the monitors are designed to default to an appropriate number of
pages for swapping. In most cases, you can take this default.

The guidelines in Table 4-5 apply to systems whose users perform many
editing jobs and an average or small amount of debugging programs and
production jobs. If your users perform a great number of debugging
and production jobs and only a small amount of editing, you should
double the size of your swapping space. However, if you double the
size of your swapping space, check the maximum swapping space allowed
_______ __ _____ _ ____________
for the monitor you are running. (The TOPS-20 KL Model B Installation
_____
Guide lists the maximum number of swapping pages you can use with each
monitor.) You cannot exceed this maximum. If you enter a number that
is larger than the maximum, the monitor uses the maximum allowed. If
you must exceed the maximum, you can bring up a larger existing
monitor, or you can tailor your monitor by following the instructions
in the BUILD.MEM file. This file is located in the documentation
files saveset on the TOPS-20 Software Distribution tape.

Table 4-5: Determining Swapping Space
Table 4-5: Determining Swapping Space

__________________________________________________________________

Estimated Recommended Number of
Estimated Recommended Number of
Number of Jobs Pages for Swapping*
Number of Jobs Pages for Swapping*
__________________________________________________________________

20 or less 3000

21 to 30 4500

31 to 40 6000

41 to 50 7500
__________________________________________________________________

* For each additional 10 jobs, increase the number of pages for
swapping by approximately 1,500.

If disk space is available, it is better to overestimate the
swapping space needed. If not enough swapping space has been
reserved, system service may be disrupted.

| If you include the ENABLE JOB0-CTY-OUTPUT command in the
| n-CONFIG.CMD file, the operator is notified at the console terminal
| when swapping space becomes low.

4-20
CREATING STRUCTURES
CREATING STRUCTURES

4.8 DETERMINING THE AVAILABLE DISK SPACE
4.8 DETERMINING THE AVAILABLE DISK SPACE

4.8.1 Determining Disk Space Before Installation
4.8.1 Determining Disk Space Before Installation

To determine the available disk space that you will have to divide
among your users before installing the system, first calculate the
swapping space required by your system (Section 4.7.2). Second,
insert the number you calculated for swapping space into the formula
shown in Table 4-6, and perform the appropriate steps.

Table 4-6 outlines how to calculate the available disk space on the
system structure. If you are calculating the available disk space on
other structures, follow this same procedure but eliminate reserving
space for any directories or areas that are not on that structure. If
any possibility exists that a structure may be used as the system
structure, reserve the swapping space.

Note that if you plan to enable the "login structure" feature in a
CFS-20 cluster (see Section 12.6.2), much more swapping space is
available on the system structures. This is because user directories
will reside on the shared login structure.

NOTE

Remember that as your system expands, the number of
pages in the and directories
increases. Also, the number of pages reserved for
directory should be increased if: (1) you
maintain large operator log files (2) users copy large
numbers of files or large files to LPT:. A large
backlog of user file retrieval requests can also use
up much of the area.

4-21
CREATING STRUCTURES
CREATING STRUCTURES

Table 4-6: Calculating Available Disk Space
Table 4-6: Calculating Available Disk Space

4-22
CREATING STRUCTURES
CREATING STRUCTURES

4.8.2 Determining Disk Space After Installation
4.8.2 Determining Disk Space After Installation

Shortly after you have installed the system, you can log in as
OPERATOR and give the command INFORMATION (ABOUT) DISK-USAGE. One
line of output tells you the actual number of system pages that are
available on the system structure. You can divide this disk storage
among your users. (Refer to Chapter 5, Creating Directories.)
However, be careful about over-allocating disk space on the system
structure. If the space allowed to user directories exceeds the space
free on the system structure after installation, then users can fill
up the entire system structure. But if TOPS-20 cannot free up
adequate space by expunging the system structure, then system service
may be disrupted. Even if space can be freed to allow the system to
keep running, some user programs may be disrupted.

4-23

5-1

CHAPTER 5
CHAPTER 5

CREATING DIRECTORIES
CREATING DIRECTORIES

A prospective user who requires access to the system must be assigned
a user name (normally the user's surname), a password, an account, and
disk storage quotas, and must have a directory created for him or her
on the public structure. Optionally, you can assign certain
capabilities and/or make the user or the user's directory a member of
one or more groups. (Refer to Section 5.8 for a description of how to
establish group relationships among users and Section 5.9 for a
description of the capabilities you can assign to users.) You can also
create additional directories for users on mountable structures.

This chapter describes three methods you can use to create and
maintain directories. Using one method, the operator creates and
maintains all the directories on the system. A second method allows
you to delegate the responsibility for creating and maintaining
directories to project administrators. The third method combines the
first two methods, thus providing additional flexibility. Sections
5.1 through 5.3 explain these methods and the determining factors for
choosing one of them. These sections also include some of the
decisions necessary to assign user names and capabilities, and how to
allocate disk storage according to the method you use to create and
maintain directories. (Refer to Chapter 4 to determine the amount of
disk space available to divide among the directories you create.)

Chapter 6 describes how to set up an accounting scheme and how to
assign and validate accounts. You should read Chapter 6 if you want
to allow users to log into the system and charge their computer usage
to valid accounts immediately after you have created their
directories.

Refer to Chapter 12, The Common File System, for considerations in
creating directories in a CFS-20 environment.

5-1
CREATING DIRECTORIES
CREATING DIRECTORIES

5.1 HAVING THE OPERATOR CREATE AND MAINTAIN ALL DIRECTORIES (CENTRAL
5.1 HAVING THE OPERATOR CREATE AND MAINTAIN ALL DIRECTORIES (CENTRAL
CONTROL)
CONTROL)

In this type of installation, the operator creates a directory on the
public structure for each new user and specifies the appropriate
parameters. The name of the directory is the same as the assigned
user name. Each user informs the operator when a change to his
directory parameters is required. This type of operation allows you
_______ _______
as system manager to have central administrative control over all
directories and parameters. Therefore, central control means that you
or the operator create and maintain all the directories for all your
system users. Central control has two types of directory schemes.
One scheme allows you to create up to approximately 5,000 directories
per structure. The other scheme allows you to use subdirectories and
create up to approximately 12,000 directories per structure.

NOTE

The number of directories allowed per structure is
approximate, because the disk space needed to create a
directory or file varies.

5.2 DELEGATING THE CREATION AND MAINTENANCE OF DIRECTORIES TO PROJECT
5.2 DELEGATING THE CREATION AND MAINTENANCE OF DIRECTORIES TO PROJECT
ADMINISTRATORS (PROJECT CONTROL)
ADMINISTRATORS (PROJECT CONTROL)

_______
An alternative type of installation involves project administrative
_______
control. Under this type of control, the operator creates directories
only for the users who have been designated as project administrators,
(e.g., the representatives of major departments). The project
administrators, in turn, create subdirectories for users within their
departments or projects and control the assignment of those users'
directory parameters. This type of control allows you to delegate the
responsibility for creating and maintaining directories for other
users and still maintain ultimate control over your system and its
resources.

Therefore, project control means that most of the directories created
by you or the operator are project directories (e.g., MATH might be
the assigned name of a project). The system's resources, such as disk
space, are divided among these project directories either equally or
according to the expected size of the project. Subdirectories are
then created under project directories for users within the project.
The people who have been appointed project leaders or administrators
are responsible for creating, assigning parameters to, and maintaining
the subdirectories within their project. The resources that you
allocate to the project directory are divided among its subdirectories
by the project administrators. Under project control, you are allowed
to create up to approximately 12,000 directories (including
subdirectories) per structure.

5-2
CREATING DIRECTORIES
CREATING DIRECTORIES

5.3 COMBINING CENTRAL AND PROJECT CONTROL
5.3 COMBINING CENTRAL AND PROJECT CONTROL

A combination of central and project control can be used if you want
to keep the majority of the user directories at the management level
of control and separate only a portion of your system into projects
and administrative control.

Therefore, combining central and project control means that the
operator creates and maintains directories for most of the system
users and creates project directories for special projects. The
project administrators create directories under the project
directories and are responsible for maintaining them. Combining the
two types of control still allows up to approximately 12,000
directories per structure.

5.4 CENTRAL AND PROJECT CONTROL DESCRIPTIONS
5.4 CENTRAL AND PROJECT CONTROL DESCRIPTIONS

Sections 5.4.1 through 5.4.4 describe the two types of central
control, project control, and the combination of central and project
control. Each description includes:

o The determining factors for choosing a particular control

o The directory format for each type of control

o The procedure for assigning user names

o The procedure for creating user directories

o The procedure for creating files-only directories

o The restrictions, if any, that apply to using a particular
control

Also, any additional considerations that apply to headings within each
description are included.

Read each description thoroughly. The first central control
description contains very general information and suggestions that
apply to all the directory schemes.

5-3
CREATING DIRECTORIES
CREATING DIRECTORIES

5.4.1 Central Control
5.4.1 Central Control

___________ ________
DETERMINING FACTORS:

o Your business installation is relatively uncomplicated;
therefore, there is no need to separate projects and assign
the creation and control of directories to various
administrators. All the directories on the system are
created and maintained by you or the system operator.

o You are sure that the number of directories you need is less
than approximately 5,000.

_______
FORMAT:

can point to approximately 5,000 directories per
structure.

All directories under are on one level.

_________ ____ ______
ASSIGNING USER NAMES:

The user name that you assign should include the user's last name.
This convention is true for any type of directory scheme that you use.
The system uses this name when recording the authors of files, sending
mail to users, and displaying system status. If you follow this
convention, you can easily identify who is using the system when you
give a SYSTAT command. If just using last names will not result in
duplications, you can simply use the last names. Otherwise, you might
want to use the first and middle initials followed by the last name.
(If a user has no middle initial, you can use a dash in its place.) It
is most convenient for users when user names begin with unique
characters, allowing use of "recognition" when typing user or
directory names. Use of leading initials often yields this result.

________ ____ ____________
CREATING USER DIRECTORIES:

All directories are created using the ^ECREATE command. (Only users
who have WHEEL or OPERATOR capability enabled can use this command.)
In the next example, the operator is connected to the public structure
PUBLIC: and uses the ^ECREATE command to create a new directory named
for the user who has been assigned the user name BECKER.
Also, the operator assigns the password MARTIN.

______ _____
@ENABLE (CAPABILITIES)
________ ____________________
$^ECREATE (NAME) PUBLIC:
[NEW]
________ ___________
$$PASSWORD MARTIN
_____
$$
_______ _____
$DISABLE (CAPABILITIES)
@

5-4
CREATING DIRECTORIES
CREATING DIRECTORIES

This directory is called the user's logged-in directory and is always
on the public structure. Whenever the user logs into the system, he
is connected to this directory. He can remain in this directory or
connect to and use files in another directory.

_______ ________ _______ ________ _________ ______
Refer to the TOPS-20 Operator Command Language Reference Manual for a
complete description of the ^ECREATE command that the operator uses to
create new directories, and the ULIST program that prints information
about all the directories on the system.

After creating a new directory (either files-only or user), remember
to update the tape containing the monitor, TOPS-20 Command Processor,
DLUSER, DLUSER data, DUMPER, , and . (Refer to
Chapter 7, System Backup Procedures.)

_______________
CONSIDERATIONS:

If two users have mistakenly been assigned the same user name and you
try to create the second directory with this duplication, the system
prints [OLD] instead of [NEW]. Give the ABORT subcommand, assign the
user a slightly different user name, and reissue the ^ECREATE command
with the new directory name. A common practice is to precede such
names with the user's first initial. This allows recognition on the
user or directory name without typing the entire name and the
distinguishing character. For instance, if you have the two users
Stephanie Sheldon and Andrew Sheldon, you should assign them the user
names S-SHELDON and A-SHELDON or SSHELDON and ASHELDON rather than use
the names SHELDON-S and SHELDON-A.

________ __________ ____________
CREATING FILES-ONLY DIRECTORIES:

If a user wants to have a library area in addition to his logged-in
directory, you can create a files-only directory on the public
structure or on another structure. The user can gain owner privileges
to this directory by giving the CONNECT command and the password
associated with the directory. If the directory is located on a
regulated mountable structure,the user must also give the MOUNT
command to use the structure before he gives the CONNECT command. The
user cannot give the ACCESS command for or log into a files-only
directory. For example, if you have a user named BECKER who processes
payroll on a regular basis, he may want to develop the payroll
programs in his directory and keep the payroll data in a more
restricted directory. To accomplish this, you can create on the
public structure the logged-in directory and the files-only
directory . The directory can be on some other
structure, (e.g., ADMIN:). BECKER now has normal protection
on his directory, more restrictive protection on the directory
and can still CONNECT to by giving its password.
BECKER cannot, however, give the ACCESS command for or log into
.

5-5
CREATING DIRECTORIES
CREATING DIRECTORIES

The next example shows how to create the directory on the
public structure MAIN:.

______ _____
@ENABLE (CAPABILITIES)
________ ___________________
$^ECREATE (NAME) MAIN:
[NEW]
________ ___________
$$PASSWORD MONIES
_____ _____
$$FILES (ONLY)
__________ ___________
$$PROTECTION (OF DIRECTORY) 774000
_______ __________ ___________
$$DEFAULT (FILE) PROTECTION 770200
_____
$$
_______ _____
$DISABLE (CAPABILITIES)
@

Now if user BECKER logs in and wants to use the files in , he
can give the following CONNECT command:

_______ ______________
@CONNECT (TO DIRECTORY)
___________
Password: monies

_______ ________ _______ ________ _________ ______
The TOPS-20 Operator Command Language Reference Manual describes all
the parameters you can give to directories and describes how to create
directories on mountable structures.

_______________
CONSIDERATIONS:

When you create additional directories on mountable structures,
consider if files-only directories are suitable. Some users will not
want to give the CONNECT command to a directory each time they require
owner access to the files in that directory. Also, files-only
directories are members of groups only as directory group members and
not user group members. Therefore, if you create ALL the directories
on a structure as files-only, you cannot establish any valid user
group relationships among those directories. (Refer to Section 5.8
for a description of setting up groups.)

Conversely, if you create user directories, users can give the ACCESS
command to their additional directory and gain owner and group
privileges without connecting to the directory, and they can use other
directories on the structure as group members. Also, if the name of
the directory you create is the same as the user's logged-in
directory, and the structure is mounted as DOMESTIC, the user does not
have to specify a password when giving the CONNECT or ACCESS command
to the directory. (Refer to Section 4.5.7.) This is valuable when the
user is submitting a batch job. No password is required on the batch
input; therefore, security is preserved. In addition to creating user
directories on the structure, you can create files-only directories to
be used as library areas.

5-6
CREATING DIRECTORIES
CREATING DIRECTORIES

It is also possible to create only one user directory on a structure
and to create all other directories as files-only. In this case, all
users required to use a files-only directory on the structure could
give the ACCESS command to the user directory (gaining owner and group
privileges), and use the files in a files-only directory according to
the group protection codes set. This would be useful if you have a
private structure that contains several library areas that are common
to the owners of the private disk pack(s). Each owner could give the
ACCESS command for the one user directory and gain group privileges to
all the library directories. Therefore, these users would need only
one password to gain access to all the information on the pack.

Note that defined groups may provide better security controls than
passwords. If the password for the ADMIN: directory is
MONIES, it might be guessed, or user BECKER may write it down or tell
it to some other user. On the other hand, group membership can be
centrally controlled, and the access can be withdrawn, if necessary.
Also, the directory structure provides a record of group memberships,
which can be displayed with the ULIST program. Wise use of directory
protections can allow user members of a group to connect to a
files-only directory without giving a password.

_______ ______ _____ _______ ________ _________
Refer to the TOPS-20 User's Guide or the TOPS-20 Commands Reference
______
Manual for a complete description of the CONNECT and ACCESS commands.

_____________
RESTRICTIONS:

The number of directories you create per structure cannot exceed
approximately 5,000. This number is an approximation because the disk
space that it takes to create a directory or file varies.

5.4.2 Central Control Using Subdirectories
5.4.2 Central Control Using Subdirectories

___________ ________
DETERMINING FACTORS:

o As stated in the previous directory scheme, your installation
does not warrant segregation of projects and control.
However, this directory scheme allows more directories per
structure than the previous central control scheme. You or
the operator can create up to approximately 12,000
directories per structure and assign and maintain all the
directory parameters.

o You can easily expand into a form of project control by
adding project directories, and still maintain control at the
management level over the majority of the user directories.
(Refer to Section 5.4.4, Combined Central and Project
Control.)

5-7
CREATING DIRECTORIES
CREATING DIRECTORIES

_______
FORMAT:

points to 26 directories. The name of each directory
is a letter of the alphabet, , , , ..., . The directories
point to all user and files-only directories. The single-letter
directories are on one level below . The user and
files-only directories are on a second level below
and are pointed to by the alphabetic directories.

Also, the directories pointed to by the single letter directories,
(e.g., ), can be allowed to create directories under them.
Perhaps user A. JONES wants to create one or two subdirectories to
store special files, such as memos. The user is responsible for
maintaining the directory he created and is allowed to use only the
disk quota you originally allocated to his logged-in directory. Refer
to Section 5.4.3, Project Control, if you would like to allow some
users to create directories of their own.

_________ ____ ______
ASSIGNING USER NAMES:

Each user name that you assign should be as close as possible to the
user's last name prefixed by a first initial and a period. For
example, Charles Baker would be assigned the user name C.BAKER. Under
this type of directory scheme, you must follow the principle of
prefixing the name with the first initial and a period.

________ ____ ____________
CREATING USER DIRECTORIES:

Have the operator create 26 directories using the ^ECREATE command.
The name of each directory is a letter of the alphabet, that is,
through .

The theory behind creating these alphabetic directories is the same as
described in Section 5.4.3. That is, you must create directories that
are allowed to have subdirectories. The directories , , ...,
can have approximately 5,000 user and files-only directories under
them. Therefore, you must include some of the same parameters in
these directories, as you would in project directories.

_______ ________ _______ ________ _________ ______
Refer to the TOPS-20 Operator Command Language Reference Manual for a
complete description of the parameters that are defined when the
operator uses the ^ECREATE command to create directories, and the
ULIST program that prints information about all directories on the
system.

The procedures for creating the alphabetic directories and the user
and files-only directories under them are described below. In the
example, COMMON: is the name of the public structure.

5-8
CREATING DIRECTORIES
CREATING DIRECTORIES

NOTE

The general considerations described in Section 5.4.1
for creating directories are also applicable to this
directory description.

Even though the alphabetic directories are not associated with users,
they must be created as log-in directories. However, do not assign
passwords. This prevents users from gaining access to these
directories.

______ _____
@ENABLE (CAPABILITIES)
________ _______________
$^ECREATE (NAME) COMMON:
[NEW]
$$

Assign each directory a large number for creating subdirectories, for
example, 400.

_______ ______________ ________
$$MAXIMUM SUBDIRECTORIES (ALLOWED) 400

Because many user directories are created under each of these
alphabetic directories and the page quota (disk space) from these
alphabetic directories is divided among (or passed on to) the user
directories, you must assign the alphabetic directories a very large
permanent and working page quota. Assigning them a sufficiently large
page quota prevents any of these alphabetic directories from exceeding
their page quota, thus requiring you to make a change to the quota at
a later time. Therefore, assign each directory at least 500,000 pages
of permanent and working disk page quota.

_________ ___________
$$PERMANENT (DISK STORAGE PAGE LIMIT) 500000
_______ ___________
$$WORKING (DISK STORAGE PAGE LIMIT) 500000

Assign a list of SUBDIRECTORY-USER-GROUP numbers to each directory.
The list should be the same for each directory. The range of numbers
you use depends on how many groups you plan to establish, (e.g., 5
groups, 10 groups, 40 groups). The numbers used in the following
examples are for illustration; you can choose any sequence:

_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 200
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 201
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 202
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 203
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 204

Later, when you create a user directory and place that user in a user
group, you must enter one of the numbers in this list. No other
numbers will be valid. (Refer to Section 5.4.3, for a more detailed
description of why you are using this list of numbers, and Section 5.8
for establishing valid group relationships.)

5-9
CREATING DIRECTORIES
CREATING DIRECTORIES

In the following example, the operator is connected to the public
structure COMMON: and creates the first two directories, and :

______ _____
@ENABLE (CAPABILITIES)
________ _______________
$^ECREATE (NAME) COMMON:
[NEW]
______________________ ________
$$MAXIMUM-SUBDIRECTORIES (ALLOWED) 400
_______ ___________
$$WORKING 500000
_________ ___________
$$PERMANENT 500000
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 200
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 201
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 202
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 203
_______________________ ________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 204
_____
$$
$
________ _______________
$^ECREATE (NAME) COMMON:
[NEW]
___ ___ _____
$$MAX 400 !You can use abbreviations
_______ ___________
$$WORKING 500000
_________ ___________
$$PERMANENT 500000
___ ________
$$SUB 200
___ ________
$$SUB 201
___ ________
$$SUB 202
___ ________
$$SUB 203
___ ________
$$SUB 204
_____
$$
$ !Continue creating directories
$ !through in exactly the same manner.

After all 26 directories are created, you can give the DIRECTORY
command to see all the directory files that have been created under
.

___ _______________________
$DIR COMMON:

COMMON:

A.DIRECTORY.1
B.DIRECTORY.1
C.DIRECTORY.1
.
.
.
Z.DIRECTORY.1

Next, after all 26 alphabetic directories have been successfully
created, the operator again uses the ^ECREATE command and creates all
the user directories.

5-10
CREATING DIRECTORIES
CREATING DIRECTORIES

In the example below, the operator is connected to the public
structure COMMON: and creates a directory named for the
user who has been assigned the user name A.JONES. This directory is
A. Jones' log-in directory on the public structure. Each time A.
Jones logs into the system, he is connected to directory .
In this example, the operator also assigns the password 2BY4. The
operator gives the directory the system default of 250 pages for both
working and permanent disk quota. Because he is using the default, he
does not have to make any entries for these two parameters. The 250
pages given to this directory are taken from the superior directory's
quota (directory ). (The PRESERVE subcommand can be issued to
avoid having the disk space quota subtracted from the superior
directory's allocation.) The operator also places user A.JONES in user
group 202 and places directory in directory group 202.

______ _____
@ENABLE (CAPABILITIES)
________ _____________________
$^ECREATE (NAME) COMMON:
[NEW]
________ _________
$$PASSWORD 2BY4
_____________ ________
$$USER-OF-GROUP (NUMBER) 202
_______________ ________
$$DIRECTORY-GROUP (NUMBER) 202
_____
$$
_______ _____
$DISABLE (CAPABILITIES)
@

After creating any new directories (either files-only or user), you
should update the backup tape that contains the monitor, TOPS-20
Command Processor, DLUSER, DLUSER data, DUMPER, , and
. (Refer to Chapter 7, System Backup Procedures.)

_______________
CONSIDERATIONS:

If users have duplicate first initials and last names, you can use
middle initials. For example, if two users have the name C.BAKER, you
can assign either one of them a user name in the form CL.BAKER or
C.LBAKER. If you use the form CL.BAKER you must create a directory
in addition to directory . If you do not create this
additional directory with the user's first and middle initial, you
will receive error messages and will not be able to create the
directory . If, instead, you assign user Baker the user
name C.LBAKER (the preferred method), you can create the directory
as described above using the standard procedure. You do
not need to create the additional directory . Alternatively, you
could create two levels of "initial" directories, and assign users to
third-level directories based on their first and middle initials
followed by their last names, for example, C.L.BAKER.

If a user requires special capabilities to perform privileged
functions, the operator can include the parameter for the capability
in the user's directory accordingly. (Refer to Section 5.9 for a
description of the capabilities you can assign to certain users who
require them.)

5-11
CREATING DIRECTORIES
CREATING DIRECTORIES

________ __________ ____________
CREATING FILES-ONLY DIRECTORIES:

If a user wants a library area in addition to the logged-in directory,
you can create a files-only directory.

Files-only directories can also be prefixed by a letter and a period.
Because the first name initials of users do not always encompass every
letter in the alphabet, you may want to use those infrequently used
letters as the prefix to the files-only directories, e.g.,
or . Alternatively, you can place the files-only directories
under a special prefix, such as LIB., or place them directly under the
root directory. The example below shows how to create the directory
on the public structure PUBLIC:. The operator assigns the
password SQUASH, makes the directory files-only, takes the 250-page
default for working and permanent disk storage quotas, and places the
directory in directory group number 202. (User members of groups 202
can now accesss this directory and the files it contains according to
group protections.)

______ _____
@ENABLE (CAPABILITIES)
________ ______________________
$^ECREATE (NAME) PUBLIC:
[NEW]
________ ___________
$$PASSWORD SQUASH
_______________
$$FILES-ONLY
_______________ ________
$$DIRECTORY-GROUP (NUMBER) 202
_____
$$
_______ _____
$DISABLE (CAPABILITIES)
@

_______ __________ _____
Follow the procedures in the TOPS-20 Operator's Guide for creating
directories on mountable structures.

_______________
CONSIDERATIONS:

The CONSIDERATIONS described in the previous central control
description (Section 5.4.1) for files-only directories also apply to
this description.

5-12
CREATING DIRECTORIES
CREATING DIRECTORIES

If the number of files-only directories you want to create is small,
you can create them on the same level as the alphabetic directories.
That is, can be created as . Your directory scheme
may look like:

------------------
| | |
| | |

... ...
--------------------------
| |
| |

or:

... ... ...
---------
|
|

_____________
RESTRICTIONS:

The number of directories you can create per structure cannot exceed
approximately 12,000.

The number of subdirectories under a single-letter directory, for
example, , cannot exceed approximately 5,000.

If you reach the maximum number of directories allowed per structure,
the system prints the message:

?MAXIMUM DIRECTORY NUMBER EXCEEDED -- INDEX TABLE NEEDS EXPANDING

5-13
CREATING DIRECTORIES
CREATING DIRECTORIES

If you reach the maximum number of subdirectories that a single letter
directory can point to, the system prints the message:

?SUPERIOR DIRECTORY FULL

You can define up to only 40 user groups with the ^ECREATE command,
because all the user groups must be specified as subdirectory user
groups in the superior single-letter directory. This is not as great
a problem when all the user directories are directly under the
ROOT-DIRECTORY.

If you make a superior directory FILES-ONLY, be sure to make all its
subdirectories FILES-ONLY. Otherwise, you will be unable to recreate
the subdirectories (refer to Chapter 9) if the structure is damaged,
until all the superior directories are made not FILES-ONLY.

5.4.3 Project Control
5.4.3 Project Control

___________ ________
DETERMINING FACTORS:

o The complexity and perhaps geography of your organization
warrants separating small or large groups of users into
projects. The responsibility for creating and maintaining
the directories within a project can be given to an
administrator. This is especially helpful if a large number
of users have directories on the system. This method frees
the operator from spending an excessive amount of time
creating directories and changing directory parameters.

o Even though you delegate the task of creating and managing
groups of directories to project administrators, you still
maintain ultimate control of the overall system and its
resources. This means that you still determine and allocate
the disk space that each project uses. The administrator
distributes the disk space you allocate to directories within
the project. Also, administrators can create and maintain
directories for their projects without having WHEEL or
OPERATOR capabilities by using the TOPS-20 BUILD command.
Therefore, you do not weaken the security of your system.
Unless you give WHEEL or OPERATOR capabilities to an
administrator, he cannot assign those capabilities to other
users.

5-14
CREATING DIRECTORIES
CREATING DIRECTORIES

o In addition to allowing administrators to create directories
for a project, you can allow other users of the system to
create subdirectories. These users can separate and store
files in a subdirectory. According to the protection they
place on their subdirectories, they can share their files
with other users without losing the security of their
superior directory. The users are responsible for
maintaining the directories they create.

o Up to 12,000 directories (including subdirectories) can be
created per structure.

_______
FORMAT:

can point to approximately 5,000 directories per
structure.

Each directory under can point to approximately 5,000
subdirectories.

Each subdirectory can also point to approximately 5,000 subdirectories
directly under it.

The number of subdirectory levels is determined by a maximum length of
39 alphanumeric characters, because each subdirectory name contains
the name or names of any superior directories above it. For example,
the user who owns directory under creates
the subdirectory . The new subdirectory name (LAB-12)
has its superior directory's name (PHYSICS) as its prefix. The period
separates the different levels of the directory name and is counted as
one of the characters in the directory name.

_________ ____ ______
ASSIGNING USER NAMES:

The names that you assign to users should be as close as possible to
the user's last name. In addition, the project names that you assign
and that will be used for project directory names should be closely
related to the project, e.g., PHYS might be used for Physics and PHYED
for Physical Education.

When you give a SYSTAT command, the user surnames and obvious project
names make it easier to identify who is using the system, and under
which project.

________ _______ ___ ____ ____________
CREATING PROJECT AND USER DIRECTORIES:

The user and project directories that points to
(first-level directories) are created by you or the operator using the
^ECREATE command.

5-15
CREATING DIRECTORIES
CREATING DIRECTORIES

The procedures you should use and the parameters that you must include
in these directories are described below.

Create all project directories as log-in (user) directories. You
would not create a project directory as files-only, because files-only
directories cannot have log-in directories created under them.
However, log-in project (or user) directories can have both log-in and
files-only subdirectories.

Assign a disk storage quota to each project directory. This quota
must be large enough to accommodate both the files that are contained
in the directory and the directories that are created under it. Each
time a directory is created under a project directory, that
directory's disk quota is taken from the project directory's disk
quota. The total disk quota for directories created under a project
directory cannot exceed the quota originally given to the project
directory.

In the example below, the operator begins to create the project
directory . He creates the directory as a log-in directory on
the public structure ORANGE: and assigns the password H20. This
procedure allows an administrator to log into the directory, giving
its password, and create the required subdirectories. He may also
want to store his files in this directory. The operator gives the
directory a 10,000-page working and a 10,000-page permanent disk
storage quota.

Next, the operator enters the parameter that allows the owner of the
project directory to create subdirectories. This parameter, called
MAXIMUM-SUBDIRECTORIES (ALLOWED), specifies how many directories can
be created under the directory. Unless you enter this parameter (the
default is 0), the owner of the directory cannot create
subdirectories. For example, all users of the system can type the
BUILD command to the TOPS-20 Command Processor, but only those users
who have the MAXIMUM-SUBDIRECTORIES (ALLOWED) parameter in their
directory with a number greater than zero can actually use the BUILD
command to create subdirectories.

5-16
CREATING DIRECTORIES
CREATING DIRECTORIES

The following entry in the sample project directory allows the
administrator to create 100 subdirectories.

______________________ ________
$$MAXIMUM-SUBDIRECTORIES (ALLOWED) 100

The administrator who is responsible for this sample project might
create 60 directories under the project directory and give each
subdirectory approximately 50 pages of working and permanent disk
quota. He keeps enough pages in the project directory to allow that
directory's files to grow and to create additional subdirectories.
_______ ________ _________ ______
(Refer to the TOPS-20 Commands Reference Manual for the description of
the BUILD command, including distributing working and permanent
storage quotas and maximum subdirectory quotas.)

Also, some of the MAXIMUM-SUBDIRECTORIES (ALLOWED) quota given to the
project directory can be given to a subdirectory so that directories
under it can be created. The quota for the project directory is
decremented by the amount of quota given to the subdirectory.

For example, directory is given a subdirectory quota of 100.
The administrator creates the directory under
and gives the directory a subdirectory quota of 10. The number of
subdirectories that can now be created under is 89. If the
administrator creates another subdirectory under called
and gives that directory a subdirectory quota of 6,
the number of subdirectories that can now be created under is
82.

___________ _________ ______
If the administrator gives an INFORMATION (ABOUT) DIRECTORY
command, the output line for maximum subdirectory quota is:

MAXIMUM NUMBER OF SUBDIRECTORIES ALLOWED 84

The two directories and that were
created under account for the two subdirectories not shown in
the subtraction.

Next, the operator enters the parameter that allows the administrator
for this project to place users in groups. The administrator can use
the group facility as described in Section 5.8 to set up library
directories and allow file sharing among members of the project.

The SUBDIRECTORY-USER-GROUP parameter accepts a number between 1 and
262143 as its argument. You can list a range of numbers that the
administrator can use to establish groups within the project; however,
you must enter each number separately. Be careful to assign a range
of numbers that is unique to that project. For example, project
directory may be given the range:

5-17
CREATING DIRECTORIES
CREATING DIRECTORIES

_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2600
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2601
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2602
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2603
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2604

Project directory may be given the following range of
numbers different from project CHEM.

_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 3001
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 3002
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 3003
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 3004
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 3005

If you assign the same range of numbers to different projects, you can
cause a security break among projects. For example, a user in group
2602 in project CHEM should not be able to access, as a group member,
the directories and files in project PHYSICS.

The range of numbers placed in a project (or user) directory's
parameter list does not imply that the directory or any of its
subdirectories has access to those groups. It means only that the
administrator (or owner of the directory) can use those group numbers
to establish group relationships among that directory and its
subdirectories.

The following example shows the completed parameter list for the
sample project directory :

______ _____
@ENABLE (CAPABILITIES)
________ __________________
$ ^ECREATE (NAME) ORANGE:
[NEW]
________ ________
$$PASSWORD H20
_______ __________
$$WORKING 10000
_________ __________
$$PERMANENT 10000
_______ ______________ ________
$$MAXIMUM SUBDIRECTORIES (ALLOWED) 100
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2600
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2601
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2602
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2603
_______________________ _________
$$SUBDIRECTORY-USER-GROUP (ALLOWED) 2604
_____
$$
_______ _____
$ DISABLE (CAPABILITIES)
@

_______ __________ _____
Refer to the TOPS-20 Operator's Guide for a complete description of
the ^ECREATE command that the operator uses to create new directories,
and the ULIST program that prints information about all the
directories on the system.

5-18
CREATING DIRECTORIES
CREATING DIRECTORIES

After creating a new directory (either user or files-only), remember
to update the backup tape that contains the monitor, TOPS-20 Command
Processor, DLUSER, DLUSER data, DUMPER, , and .
(Refer to Chapter 7, System Backup Procedures.)

_______________
CONSIDERATIONS:

If two projects or users have mistakenly been assigned the same name,
and you try to create the second directory with this duplication, the
system prints [OLD] instead of [NEW]. Give the ABORT subcommand,
assign the user or project a slightly different name, and reissue the
^ECREATE command with the new directory name.

A subdirectory is just like any other directory. It can be logged
into (if it is not specified as files-only), it can be a member of
user and directory groups, and it obeys the usual protection
mechanisms. Therefore, there are no implied rights between a
directory and its subdirectories, or between two subdirectories of the
same directory. Files have three protection fields: owner, group,
and world; and each directory has the same three protection fields.
Refer to Section 5.7 for a description of directory and file
protections.

The only additional rights that the owner of a directory has over that
directory's subdirectory is the power to change its parameters (e.g.,
directory protection, password, or group memberships), or to use the
KILL subcommand, which deletes the subdirectory.

5-19
CREATING DIRECTORIES
CREATING DIRECTORIES

If you or another user choose to delete a directory, you must first
delete any subdirectories under the directory. You cannot delete a
directory or subdirectory that has existing subdirectories. This
protection insures that someone (possibly an administrator of a
project) does not accidentally delete a directory that points to a
large portion of the database. The operator or administrator must
connect to the directory immediately above the lowest level
subdirectory to begin deleting any directories. For example, if the
owner of the directory wants to delete the directory
, he must first connect to directory
and delete any of its subdirectories. Then, he connects to directory
and gives the KILL subcommand to delete directory
. Note that the operator is the only person who can
delete the directory .

If you or the administrator choose to grant special capabilities to a
user, you can include the parameter for the capability in the user's
directory. (Refer to Section 5.9 for a description of the
capabilities you can assign to certain users.) You should instruct the
administrator to inform you when special capabilities are given to a
system user. You are protected against users randomly giving other
users special capabilities, because the operator or the administrator
who assigns special capabilities to a user must have (as a user) those
same capabilities. A person with WHEEL or OPERATOR capabilities can
assign any capability to another user. Also, the user or operator who
is assigning the capabilities must have those capabilities enabled at
the time the privileged parameter is entered into the user's
directory.

Once a SUBDIRECTORY-USER-GROUP number has been allocated to a project
directory, be careful about removing it. If it is in use in any of
the subdirectories, either as a USER-OF-GROUP number or as a
SUBDIRECTORY-USER-GROUP number, you will be unable to recreate the
subdirectories (refer to Chapter 9) if the structure is damaged, until
you manually restore the SUBDIRECTORY-USER-GROUP number into all the
superiors.

5-20
CREATING DIRECTORIES
CREATING DIRECTORIES

________ __________ ____________
CREATING FILES-ONLY DIRECTORIES:

Administrators or users can have library areas in addition to their
logged-in directories. They can use the BUILD command and create
files-only directories under their logged-in directories, provided you
have given them the capability to do so by adding the MAXIMUM
SUBDIRECTORIES (ALLOWED) parameter to the directory that will contain
the subdirectories.

_______________
CONSIDERATIONS:

Refer to the CONSIDERATIONS under the first description of Central
Control, Section 5.4.1. These considerations also apply to Project
Administrative Control.

_____________
RESTRICTIONS:

o You cannot exceed approximately 12,000 directories per
structure.

o The number of directories that a superior directory points to
cannot exceed approximately 5,000.

If you reach the maximum number of directories that you can create on
a structure, the system prints the message:

?MAXIMUM DIRECTORY NUMBER EXCEEDED -- INDEX TABLE NEEDS EXPANDING

If either you or an administrator reach the maximum number of
directories that can be created under a superior directory, the system
prints the message:

?SUPERIOR DIRECTORY FULL

o Files-only directories cannot have log-in subdirectories. If
you want to allow a user to create user (log-in)
subdirectories under his directory, you must make his
directory a log-in directory.

5-21
CREATING DIRECTORIES
CREATING DIRECTORIES

5.4.4 Combined Central and Project Control
5.4.4 Combined Central and Project Control

___________ ________
DETERMINING FACTORS:

o Only a portion of your organization warrants being separated
into projects. The directories for the majority of the user
community are created and maintained at the central
management level. But, where project administration is
appropriate, the task of creating and managing directories
within a project is given to administrators.

o For example, if your company has groups of users with
terminals in several distant locations, you may want to have
the administrator at the remote location create and maintain
all the directories for that site. You can create a project
directory for the remote location, perhaps using the name of
the site as the project directory name (for example,
or , , ...). The remaining user
directories at the central location are created by the system
operator.

_______
FORMAT:

points to all the project directories and 26
alphabetically named directories, through . The project
directories point to the user and files-only directories that an
administrator creates for a given project. The directories
through point to user and files-only directories created and
maintained by the operator. These directories can also be allowed to
have subdirectories.

_________ ____ ______
ASSIGNING USER NAMES:

If you create any user directories that are pointed to by
, assign project names and user names in the same
manner as described under Project Control, Section 5.4.3. Again,
assign the 26 directories that will point to the majority of the user
directories, the names , , .... . The user names that
will be the directory names under the alphabetic directories should,
as previously stated, be the user's surname prefixed by a first
initial and a period. (Refer to Section 5.4.2, Central Control Using
Subdirectories.)

________ ____ ___ __________ ____________
CREATING USER AND FILES-ONLY DIRECTORIES:

Create the user, files-only, and through directories by
following the instructions in Section 5.4.2.

Create the project directories according to the instructions in
Section 5.4.3, and distribute the description of the BUILD command
_______ ________ _________ ______
(TOPS-20 Commands Reference Manual) to the administrators who are
responsible for creating the user directories within their project.

5-22
CREATING DIRECTORIES
CREATING DIRECTORIES

_______________
CONSIDERATIONS:

All the considerations that apply to both Central and Project Control
also apply to combining the two types of control.

You may want to allow users whose directories are created by the
operator to create several directories under their logged-in
directories. For example, user A.SMITH creates the subdirectory
to store files that he wants to keep separate from his
programming files. This user uses the BUILD command to create the
number of subdirectories that he is allowed to create and divides the
quota for his logged-in directory among the directories he creates.

In general, users can store files in these directories or, if they set
the appropriate protection, can share the files in these directories
with other users.

_____________
RESTRICTIONS:

Combined Central and Project Control allows up to approximately 12,000
directories per structure.

The number of directories that a superior directory can point to
cannot exceed approximately 5,000.

If you reach the maximum number of directories per structure, the
system prints the message:

?MAXIMUM DIRECTORY NUMBER EXCEEDED -- INDEX TABLE NEEDS EXPANDING

If you reach the maximum number of directories that a superior
directory can point to, the system prints the message:

?SUPERIOR DIRECTORY FULL

5.5 ALLOCATING DISK STORAGE QUOTAS
5.5 ALLOCATING DISK STORAGE QUOTAS

In Chapter 4 you determined the amount of disk space that is available
on the system structure after installation. Once you know the
available disk space, you can decide how to allocate it among the
directories you create. Each directory is given a number of pages for
both working-storage and permanent-storage allocations. Working
storage refers to the disk space that a user can have during the time
he is logged-in. Permanent storage refers to the total disk space
that a user can have to store files after he has logged-out.

5-23
CREATING DIRECTORIES
CREATING DIRECTORIES

The number of pages that you should assign to directories depends on
whether you (or the operator) are creating all the directories on the
system (central control) or you are delegating the task of creating
and maintaining directories to project administrators (project
control). When using central control, you may divide the disk space
equally among directories, giving regard to special requirements of
certain users. In the case in which the operator creates project
directories, you should allocate a disk quota large enough to
accommodate the expected size of each project. Remember that project
directories must distribute their disk space to the directories
created under them.

Several important points about working and permanent allocations are
discussed below.

Assign a large (2000-3000 page) working-storage allocation to users
who perform considerable sorting because the temporary files required
for this operation can occupy substantial disk space.

As the number of users on the system increases and your disk space on
the public structure becomes low, you can decrease the working-storage
and permanent allocations on the public structure to add new log-in
directories. If you have additional disk drives not used by the
public structure, you can accommodate the directories with many or
large files by creating other structures and directories. Users will
log into their directories on the public structure, request the
operator to mount the proper structure using the MOUNT command, and
access their additional directories with the ACCESS and/or CONNECT
command. Note that in setting up the system, it is easier to accustom
users from the start to use other structures than to reorganize the
structures and retrain users after space has run out on the public
structure.

5.6 ENFORCING DISK STORAGE QUOTAS
5.6 ENFORCING DISK STORAGE QUOTAS

Working-storage allocations are strictly enforced. Users cannot
exceed their working-storage allocations unless they enable WHEEL or
OPERATOR capabilities. (Refer to Section 5.9 for a description of the
special capabilities that can be given to users who require them.) If
users request additional space, you can increase their allocations as
required.

If a user exceeds his working-storage allocation and attempts to
create or change a file, the system prints the following error
message:

?QUOTA EXCEEDED The user must decrease his disk usage to less than the
working-storage allocation for the directory (in which the file is
being changed or created) before he can create or change any more
files.

5-24
CREATING DIRECTORIES
CREATING DIRECTORIES

The system informs a user if he is over this permanent storage
allocation when he logs off the system or connects to a different
directory. The system prints the following message after the CONNECT
or LOGOUT commands:

OVER PERMANENT STORAGE ALLOCATION BY nn PAGES

This message reminds users that although they may not be over their
working-storage allocation, they have exceeded their expected total
disk usage. Users should delete any files that are unnecessary for
their job. Also, because permanent quotas are not enforced, it is
wise to instruct the operator or administrator to police each
directory's disk usage. The operator should run the CHKPNT program
_______
daily to keep a record of each directory's disk usage. The TOPS-20
__________ _____
Operator's Guide contains the description of running the CHKPNT
program. If you are using the file migration facility (refer to
Chapter 8), you may want to run the REAPER program with the TRIM
command to force users to stay below their permanent quotas.

Every time the available disk space on the system structure is less
than 500 pages, the system prints the following warning messages:

13-Jun-98 10:20:33 Disk space low on structure STR:, 122 free

[STR: Deleted files will be expunged from structure STR: in 30
seconds]

After 30 seconds, the system starts expunging any deleted files in all
directories on the structure mentioned in the warning message.

The system prints this message when the expunging is complete:

[STR: Expunge of structure STR: completed]

The operator gets the following message:

13-Jun-89 10:59:59 Expunge completed for structure STR:, 1993 free

If anyone tries to create or change a file when there is no more disk
space available, the system prints an error message similar to the one
below:

?FILE OR SWAPPING SPACE EXCEEDED

Again, the operator or administrator should check to see how many
users are over permanent allocations. Also, if you are using the file
migration facility, you may want to migrate files on the system more
frequently if you are constantly running low on systemwide disk space.
(Refer to Chapter 8 for a description of file migration.)

5-25
CREATING DIRECTORIES
CREATING DIRECTORIES

5.7 PROTECTING DIRECTORIES AND FILES
5.7 PROTECTING DIRECTORIES AND FILES

Every directory and file has a protection number associated with it.
The system uses a default protection number for each directory and
file when the directory or file is created.

Whenever a user accesses a file, the system first checks the directory
protection. If that protection allows the user the appropriate access
to the directory, the system then checks the protection of the
individual file.

5.7.1 Directory and File Protection Digits
5.7.1 Directory and File Protection Digits

The directory and file protection numbers have three 2-digit fields.
The first field applies to the owner of the directory or file, the
second field to members of the same group as this directory, and the
third field to all other users (or world).

Protection Code
____________________________________
| dd | dd | dd |
____________________________________

Owner Group World

The default protection for directories and files is 777700. A
directory or file protection of 77 in any given field allows full
access. For example, the default protection allows the owner and
members of his group full access but all other users no access.

Protection Code
___________________________________
| 77 | 77 | 00 |
___________________________________

Owner Group World

5-26
CREATING DIRECTORIES
CREATING DIRECTORIES

Table 5-1 contains a list of the directory protection digits.

Table 5-1: Directory Protection Digits
Table 5-1: Directory Protection Digits

__________________________________________________________________

Digits Privilege
Digits Privilege
__________________________________________________________________

04 Permits creating files in the directory.

10 Permits connecting to the directory without giving a
password and changing the accounts and protection
numbers of the files therein. Thus it gives many of
the privileges the directory owner has. (Refer to the
_______ _______ _____ _________ ______
TOPS-20 Monitor Calls Reference Manual.)

40 Permits, subject to the protection on the individual
file, listing the names of the files with the
DIRECTORY command and reading the file, e.g., via the
TYPE, PRINT, or LIST commands.
__________________________________________________________________

These protection codes are actually bits in a protection word. To get
more than one protection, add the digits (octal) corresponding to the
protection you want. Thus, 44 allows listing the files and creating
new files. There are unused bits in the protection number; therefore,
to provide complete access to files, use 77. Useful digit pairs are:

00 Permits no access.

40 Permits the files to be listed and read.

77 Permits full (owner) access.

A file protection number has the same format as a directory protection
number, but the meanings of the digits are different. Table 5-2
contains a list of file protection digits.

5-27
CREATING DIRECTORIES
CREATING DIRECTORIES

Table 5-2: File Protection Digits
Table 5-2: File Protection Digits

__________________________________________________________________

Digits Privilege
Digits Privilege
__________________________________________________________________

02 Permits wildcarding of the file.

04 Permits appending to the file.

10 Permits executing the file.

20 Permits writing and deleting the file.

40 Permits reading the file.
__________________________________________________________________

Obtain a protection number by adding the file protection digits of the
different protections you need. For example, protection number 775200
allows the owner full privileges; the members of the same group
reading, executing, and directory listing privileges; and all other
users no privileges. Useful digit pairs are:

00 Permits listing the file with the DIRECTORY command only if the
file is specified explicitly and completely.

12 Permits executing and using the DIRECTORY command to list the
file only.

This protection is useful when, for example, you purchase a
program and agree in your contract not to allow any of your
system users to read, write into, or copy the file. Set the
protection on an execute-only file to 771212. The TOPS-20 Beware
file provides additional considerations for setting up
execute-only files.

52 Permits reading, executing, and using the DIRECTORY command to
list the file.

77 Permits full access.

The system checks protection numbers starting with the two rightmost
digits. Therefore, users do not restrict members of a group by
assigning the file protection 770052, because the group gets at least
the execute, read, and directory list access (52) granted to all
users.

5-28
CREATING DIRECTORIES
CREATING DIRECTORIES

Also, because the system checks the directory protection before the
file protection, files that have been given a low file protection are
still secure in a directory with the default directory protection.
For example, suppose the user KOHN tries to type the file EDIT.MAC in
the directory . The protection on the directory is
777700 and the protection on the file EDIT.MAC is 777752. User KOHN
and directory are not in the same group, so the world
protection applies. First, the system checks the directory
protection, 777700. The last two digits (00) apply and permit no
access to the directory. User KOHN is not allowed to type the file,
even though the corresponding protection on the file (52) would allow
the file to be read, executed, and listed with the DIRECTORY command
if KOHN were allowed access to files in the directory.

5.7.2 Changing Directory and File Protection
5.7.2 Changing Directory and File Protection

Users can change file protection numbers via the SET FILE PROTECTION
command or the RENAME command.

Users can change directory protection numbers via the SET DIRECTORY
PROTECTION or BUILD command. You can, however, prevent users from
making changes to their directory protection numbers by including the
DISABLE DIRECTORY-PARAMETER-SETTING command in the system file called
n-CONFIG.CMD on the system structure. If you make this entry
in n-CONFIG.CMD, only users with WHEEL or OPERATOR capabilities can
change directory parameters (via the ENABLE and SET DIRECTORY
PROTECTION commands).

NOTE

Make an entry in n-CONFIG.CMD only if you DO NOT want
to allow users to change their directory protections;
otherwise, the system assumes that you want to use the
system default command of ENABLE
_______ __
DIRECTORY-PARAMETER-SETTING. (Refer to the TOPS-20 KL
_____ _ ____________ _____
Model B Installation Guide for a description of the
parameters that are placed in the n-CONFIG.CMD file.)

5.8 ESTABLISHING GROUPS
5.8 ESTABLISHING GROUPS

You can let users share files by placing users and directories in
groups. Members of a group can access directories and files in that
group according to the middle digits of the directory and file
protection code fields, as described in Section 5.7.1.

5-29
CREATING DIRECTORIES
CREATING DIRECTORIES

Each group that you establish has two types of members: USERS and
. Each group is identified by a number. This number is
included as one of the directory parameters in each directory
belonging to the group. Any directory (including subdirectories) or
user can belong to as many as 40 groups. You can set up group
relationships in the individual directories by using the
DIRECTORY-GROUP and USER-OF-GROUP subcommands to the ^ECREATE and
BUILD commands. The following example shows that you have placed user
Smith in user group 268 and directory group 418:

______ _____
@ENABLE (CAPABILITIES)
________ _________________
$^ECREATE (NAME) MAIN:
________ _________
$$PASSWORD SOAR
_______ ________
$$WORKING 500
_________ ________
$$PERMANENT 500
_____________ ________
$$USER-OF-GROUP 268
_______________ ________
$$DIRECTORY-GROUP 418
$$

The DIRECTORY-GROUP or USER-OF-GROUP parameter that you place in the
user's directory determines: 1) if this user can access another
directory's files as a group member 2) if the files in this user's
directory can be accessed by another user as a group member, or 3)
both. The diagrams on the following pages illustrate the difference
between being a member of a group as a directory and/or as a user.

When a user accesses a file in a directory that is a member of the
same group, the system first checks to see if this user is the owner
of the directory. When, in this example, it finds that the user is
not the owner, the system then checks to see if the user is in the
same group as this directory. In this case, the user and directory
are in the same group; that is, the group numbers match. The system
now checks the group protection code field of the directory being
accessed. If the group protection allows the type of access that the
user requested, the system proceeds to check the group protection on
the individual file.

If you are setting up groups on different structures, there is no
correlation between a group number on one structure and the same group
number on another structure. For example, group 202 on MAIN: does
not necessarily have the same user and directory members as group 202
on another structure.

5-30
CREATING DIRECTORIES
CREATING DIRECTORIES

_______
Example

------------------------------
| |
| |<------------------USER
| |
|DIRECTORY GROUP NUMBER LIST |
| n |
| . |
| . |
| . |
| n |
| |
| |
| |
|USER GROUP NUMBER LIST |
| n |
| . |
| . |
| . |
| n |
------------------------------

Each directory has two lists of group numbers: Directory Group
Numbers and User Group Numbers.

Directory Group Numbers identify the various groups of which this
is a member.

User Group Numbers are associated with users and identify the various
groups of which each user is a member.

5-31
CREATING DIRECTORIES
CREATING DIRECTORIES

_______
Example

----------------------------
| |
| |<----------------USER
| |
|DIRECTORY GROUP NUMBER LIST|
| n |
| . |
| . |
| . |
| n |
----------------------------

-----------------------------
|USER GROUP NUMBER LIST |
| n |
| . |
| . |
| . |
| n |
-----------------------------

The Directory Group Numbers are important to users who require access
to this directory. Those users who have a matching group number in
the User Group Number List can access this according to
its group protection code.

The User Group Numbers are important to the owner of this directory.
This owner can access any directory that has a matching group number
in its Directory Group Number List. Note: Because files-only
directories are not associated with a user, they do not contain User
Group Numbers.

There are three common types of groups:

1. A file-sharing group, whose users can access a set of library
directories and each other's logged-in directories.

2. A library group, whose users can access a set of library
directories and their own logged-in directories, but not each
other's logged-in directories.

3. A teacher-student group, in which the teacher can access the
students' directories and the students can access their own
logged-in directories, but not their classmates' directories
or the teacher's directory.

5-32
CREATING DIRECTORIES
CREATING DIRECTORIES

Figures 5-1 through 5-3 illustrate these three common groups and the
association between USER and members of a group.

In a file-sharing group (Figure 5-1), users share all their files
according to the group protection field, both in the library
directories (here it is ) and in their logged-in directories.
User PORADA User HOLLAND
_________________ _________________
| | | |
| Directory Group | | Directory Group |
| Number List | A | Number List |
| 3, 2 < 2, 4 |
| | x | | |
| User Group | x | | User Group |
| Number List | B x | | Number List |
| 1, 2------------- xxxxxxxxxxxxxxxxx 2, 6 |
|_________|_______| | | |_____x___________|
| | | x
| | | x
| ----------- x
| x
C | xxxxxxxxxxxxxxxxxx D
| x
| v
| _______v_________
| | |
| | Directory Group |
| | Number List |
----------------> 2, 8 |
| |
| User Group |
| Number List |
| None |
|_________________|

Legend:

1. A User HOLLAND can access directory

2. B User PORADA can access directory

3. C User PORADA can access directory

4. D User HOLLAND can access directory

Figure 5-1: File-Sharing Group
Figure 5-1: File-Sharing Group

5-33
CREATING DIRECTORIES
CREATING DIRECTORIES

In Figure 5-1, the two users, PORADA and HOLLAND, are members of the
same group (group 2). The directories , , and
are also members of group 2. Users PORADA and HOLLAND can
access their own directory and files according to the owner protection
code fields. PORADA can access directories and
according to the group protection code fields, and conversely, HOLLAND
can access directories and according to their group
protection code fields. The other numbers shown in the figure
indicate that a user or directory can be a member of more than one
group.

In a library group (Figure 5-2), USER members can access all the
members but not each other's logged-in directories. The
library directories are usually files-only directories. This figure
illustrates a library group that consists of the files-only
directories: , , , and users:
ALUSIC, BROPHY and KOHN. This library group illustrates that just
because you are a member of a group as a user, your logged-in
directory need not belong to the same group.

5-34
CREATING DIRECTORIES
CREATING DIRECTORIES

USER KOHN
|
V
+-----------------+
| |
| |
| DIRECTORY GROUP |
| NUMBER LIST |
| |
| 1 |
| |
| USER GROUP |
| NUMBER LIST |
| |
| 2---------|--------------
+-------|---------+ |
| |
| |
+-----------------+ | +-----------------+ | +-----------------+
| | | | | | | |
| | | | | | | |
| DIRECTORY GROUP | | | DIRECTORY GROUP | | | DIRECTORY GROUP |
| NUMBER LIST | | | NUMBER LIST | | | NUMBER LIST |
| | | | | | | |
| 2<-------|-------|------>2 | |----|------>2 |
| | | | | |
| USER GROUP | | USER GROUP | | USER GROUP |
| NUMBER LIST | | NUMBER LIST | | NUMBER LIST |
| | | | | |
| NONE | | NONE | | NONE |
+-----------------+ +-----------------+ +-----------------+

Figure 5-2: Library Group
Figure 5-2: Library Group

5-35
CREATING DIRECTORIES
CREATING DIRECTORIES

In Figure 5-2, users KOHN, ALUSIC and BROPHY are not directory group
members of the same group; however, they are all user group members in
the same group (group 2). User KOHN can access directory
according to the owner protection field and can access directories
, , and according to the group
protection field. KOHN can access and according to
the "world" protection field. Although the arrows have not been drawn
from users BROPHY and ALUSIC, their access privileges are the same as
KOHN's.

5-36
CREATING DIRECTORIES
CREATING DIRECTORIES

Figure 5-3: Teacher-Student Group
Figure 5-3: Teacher-Student Group

5-37
CREATING DIRECTORIES
CREATING DIRECTORIES

In a teacher-student group (Figure 5-3), the teacher, WILEY, is a
member of the group as a USER, while the directories , ,
, and are members. The teacher, WILEY,
can access the files in the directories , , ,
and according to the group protection. The students whose
logged-in directories are in this group as members can
access the files in according to the protection set for all
users, because only their directories are members of the group; they
are not members of the group as users.

5.9 GIVING USERS SPECIAL CAPABILITIES
5.9 GIVING USERS SPECIAL CAPABILITIES

You can give special capabilities to certain users; they are WHEEL,
OPERATOR, SEMI-OPERATOR, CONFIDENTIAL, MAINTENANCE, IPCF, ENQ-DEQ,
| INTERNET-WIZARD, and ABSOLUTE-INTERNET-SOCKETS. Each capability that
you give to a user is placed in the user's directory parameter list
when you create or change the directory. The person who enters the
capability in a user's directory must have that capability himself,
and have it enabled at the time the capability is entered into the
directory parameter list. You should grant these capabilities only to
users who absolutely need them. Table 5-3 lists all the available
capabilities and a brief description of their function.

Table 5-3: Special Capabilities
Table 5-3: Special Capabilities

__________________________________________________________________

Capability Description
Capability Description
__________________________________________________________________

WHEEL Allows the user to modify any system
parameters or data. In particular, the
WHEEL capability is needed if the user
wants to give the ^EEDDT or ^EQUIT
commands.

OPERATOR Allows the user all capabilities required
to control the system. The user cannot,
however, give the ^EEDDT or ^EQUIT
commands.

SEMI-OPERATOR Allows the user to execute only a subset of
the operator commands -- to get system
status information and to control certain
devices.

CONFIDENTIAL Allows the user to obtain accounting
information for another user's job.

5-38
CREATING DIRECTORIES
CREATING DIRECTORIES

Capability Description
Capability Description

MAINTENANCE Allows the user (usually the field service
representative) to perform certain
maintenance functions, but he cannot give
the ^E commands.

IPCF Allows the user to perform the privileged
_______
functions of IPCF. (Refer to the TOPS-20
_______ _____ _________ _______
Monitor Calls Reference Manual.)

ENQ-DEQ Allows the user to perform global
ENQUEUE/DEQUEUE functions.
|
| INTERNET-WIZARD Allows the user to perform certain INTERNET
| privileged functions.
|
| ABSOLUTE-INTERNET- Allows the user to place absolute socket
| SOCKETS numbers in his programs.
|
| INTERNET-ACCESS Allows the directory owner to establish
| INTERNET network connections.

DECNET-ACCESS Allows the directory owner to establish
DECNET network connections.
__________________________________________________________________

With the exception of WHEEL and OPERATOR, these capabilities are not
listed in a format where having one capability means you also have the
capabilities listed below it. The user who has WHEEL capabilities can
perform the OPERATOR, SEMI-OPERATOR, CONFIDENTIAL, MAINTENANCE, IPCF,
and ENQ-DEQ functions. The user who has OPERATOR capabilities can
also perform these privileged functions with the exception of the
^EEDDT and ^EQUIT commands. But the user who has CONFIDENTIAL
capabilities can only perform functions that are allowed by this
capability; that is, he cannot perform MAINTENANCE, IPCF, ENQ-DEQ,
| INTERNET WIZARD, and ABSOLUTE INTERNET SOCKETS functions, unless he
has been given the individual capability. The same principle is true
for the remaining capabilities.

Also, you are giving capabilities to a user, not the user's directory.
Therefore, if user HALL has WHEEL capabilities, other users who
connect to or access the directory do not obtain WHEEL
capabilities. However, if they log in as user HALL, they will obtain
HALL's capabilities. For this reason, users with special capabilities
(especially WHEEL and OPERATOR) should be especially careful in
selecting and protecting their passwords. They should be encouraged
to change them often, and to use passwords that cannot be readily
guessed.

5-39
CREATING DIRECTORIES
CREATING DIRECTORIES

5.10 PRINTING DIRECTORY INFORMATION
5.10 PRINTING DIRECTORY INFORMATION

The ULIST program prints information about directories on the system
_______ __________ ______
and is described in the TOPS-20 Operator's Guide. In addition to
listing information about each directory, the ULIST program can list
information about groups, capabilities, and related information.

The LIST subcommand of the ^ECREATE command prints information about
the directory or user name you are currently creating, and the ^EPRINT
command also prints the information on an individual basis.

5-40

CHAPTER 6
CHAPTER 6

CREATING ACCOUNTS
CREATING ACCOUNTS

The TOPS-20 accounting facility allows you to assign and charge
computer usage to valid accounts. It provides you with a means for 1)
adding security to your system, 2) determining charges for computer
usage and billing users by account, and 3) associating classes with
accounts for use by the class scheduler. You can use account
validation for one or all of these reasons.

One or more accounts can be assigned to a user for specific tasks and
validated each time they are used. All accounting data, including
records of CPU time, structures used, and peripherals used under a
valid account, are stored in a usage file and can be used later for
reports and billing.

This chapter describes how to set up the system to use accounts and
_______ _____ ____
establish an accounting data base. The TOPS-20 USAGE File
_____________
Specification describes how to create accounting reports from the
Usage file and establish billing procedures. The following sections
include:

o How to set up your system to use accounts

o How to select an accounting scheme

o How to use your accounting scheme and create the necessary
base account and subaccount files

o How to run the account generator program (ACTGEN), which
takes these account data files and creates the accounting
data base

o What the operator can do if the accounting data base does not
work properly

o How to initialize your system to start validating accounts

6-1
CREATING ACCOUNTS
CREATING ACCOUNTS

6.1 SETTING UP THE SYSTEM TO USE ACCOUNTS
6.1 SETTING UP THE SYSTEM TO USE ACCOUNTS

6.1.1 Enabling or Disabling Account Validation
6.1.1 Enabling or Disabling Account Validation

During software installation, you can specify whether you wish to
create the account data base and validate accounts. You can make an
entry in the n-CONFIG.CMD file that specifies either DISABLE
ACCOUNT-VALIDATION or ENABLE ACCOUNT-VALIDATION. If you do not make
an entry in the n-CONFIG.CMD file for accounting, the system assumes
ENABLE ACCOUNT-VALIDATION.

If you enter DISABLE ACCOUNT-VALIDATION, meaning you do not wish to
use the account validation facility, the system checks each account
only for length. The purpose of the check is to ensure that the
maximum number of alphanumeric characters has not been exceeded in
each account. No other checking is performed. If a user attempts to
use or create an account greater than 39 characters, the system simply
| truncates the entry to the 39-character maximum. The created entry is
| sure to be of valid length if you enable account validation in the
| future.

If you have instructed the system to ENABLE ACCOUNT-VALIDATION but
have not yet created an account validation data base, you receive a
warning on the console terminal (CTY) when the system starts
operation. The message is:

ACCOUNTS-TABLE.BIN NOT FOUND - ACCOUNT VALIDATION IS DISABLED

The system continues its normal operation; however, no accounts are
validated (except for length checking) until you create the necessary
account data files and run the account generator program (ACTGEN) to
create your account data base.

You should not receive the above warning message if you have created
your account data base prior to bringing the system up for operation.
Users can log into the system using their valid accounts.

6.1.2 Setting up Account Validation with Existing Files
6.1.2 Setting up Account Validation with Existing Files

If you are using account validation on a system that already has
files, the accounts for these existing files should be updated before
account validation is enabled in the n-CONFIG.CMD file. Notify the
users who created these files to change the existing account on every
file to their new account(s). This procedure ensures accurate billing
immediately after the system is brought up and that daily DUMPER tapes
contain files with valid accounts. This means that if you must
restore files from a backup tape, the correct account for each file is
properly restored; therefore, the disk file storage continues to be
_______ __________ _____
accurately charged. (Refer to the TOPS-20 Operator's Guide for the
procedure to follow if all files do not get updated.)

6-2
CREATING ACCOUNTS
CREATING ACCOUNTS

6.1.3 Setting up the System for Accounting Shift Changes
6.1.3 Setting up the System for Accounting Shift Changes

The accounting facility also allows you to change your billing rates
for system usage at selected times during the day. This action is
called an accounting shift change. Accounting shift changes are
selected by day-of-week and time-of-day.

You must enter the appropriate commands in the n-CONFIG.CMD file to
initiate accounting shift changes. The n-SETSPD program reads these
commands each time the system is reloaded. The format of the command
placed in the n-CONFIG.CMD file is:

CHANGE time days-of-week

You can use any format for the time and day, that is, 1500, 15:00,
3:00pm, MONDAY, MON. Or, you can use the keywords ALL, WEEKENDS, and
WEEKDAYS. The default for days-of-week is ALL. The following is a
typical set of commands that may appear in the n-CONFIG.CMD file:

______ ____ ________
CHANGE 9:00 WEEKDAYS
______ _____ _______________
CHANGE 10:00 WEEKENDS,MONDAY
______ _____ ____________________
CHANGE 12:00 TUESDAY,THURSDAY,SAT
______ _____
CHANGE 17:00

The CHANGE (ACCOUNTING SHIFT NOW) command to the CHKPNT program
provides you with a means of changing shifts during system operation.
This command causes an accounting session to end and a new accounting
session to begin for all active jobs on the system. Refer to the
_______ __________ _____
TOPS-20 Operator's Guide for a description of all the commands that
can be given to the CHKPNT program.

6.2 SELECTING AN ACCOUNTING SCHEME
6.2 SELECTING AN ACCOUNTING SCHEME

The first thing you must do before you create account data files is
set up an accounting scheme. This procedure includes deciding which
accounts you wish to create, their expiration dates if you are going
to open and close accounts, the names of the users who can use (or
charge to) those accounts and, if you are using the class scheduler,
the scheduling class associated with each account.

6-3
CREATING ACCOUNTS
CREATING ACCOUNTS

The TOPS-20 account validation facility allows several levels of
project administration in a group of accounts having the same base
account. For example:

DENVER <-----Base Account
------
|
|
|

Subaccount-----> OVERHEAD LAB-12 <-----Subaccount

The accounts you would create using the above example are:

DENVER
DENVER.CHEM
DENVER.CHEM.OVERHEAD
and
DENVER.CHEM.LAB-12

In this example, users at Denver University taking a particular lab
course in chemistry (e.g., 12) would log in and charge to their
assigned account, DENVER.CHEM.LAB-12.

All accounts that you assign to users can have a maximum length of 39
alphanumeric characters. The system allows you to use a hyphen (-)
within the accounts you create (e.g., LAB-12), but no other
punctuation (including spaces) can be used. Note that the system uses
the period (.) as a delimiter to separate each part of multi-level
accounts and the period is counted as one of the 39 characters.
Therefore, DENVER.CHEM.OVERHEAD is a user account with 20 characters.

6-4
CREATING ACCOUNTS
CREATING ACCOUNTS

The type of accounting scheme you use depends on the form of project
administration you have at your installation. Multi-level accounts
are usually created through a form of project administration similar
to that used when allowing certain users (perhaps heads of
departments) to create subdirectories. (Refer to Chapter 5, Creating
Directories.) Remember that subdirectories are just like any other
directory. Therefore, users must have accounts to log into their
directory. Generally, all files that contain data pertaining to base
accounts are created by you or the operator, and all files that
contain subaccount data are created by one, or perhaps more than one,
project administrator. A project administrator, for example, might be
the head of the Chemistry Department. (This could be the same person
who handles the subdirectory creation for a group or groups of users.)
Allocating the subaccount file creation to a project administrator
allows you to collect or budget for one base account (e.g.,
DENVER.CHEM) and not be directly concerned with the subaccounts. In
the example, the head of the Chemistry Department is responsible for
creating the subaccount files under DENVER.CHEM., that is, LAB-12 and
OVERHEAD. Section 6.3 describes how to create these account data
files using a sample accounting scheme.

Figures 6-1 and 6-2 illustrate several ways that you can set up your
accounting scheme. Figure 6-1 is a simple scheme that a small
organization might use. It also allows you, as system manager, to
have complete control over all accounts because you are aware of every
account assigned.

Figure 6-1 shows that the manager at Correct Data Company has decided
to set up one base account for Correct Data and one base account for
each customer using his system. He used the customer name for the
accounts. All the people who use the system at Correct Data can
charge their computer usage to the Correct Data account, CORRECT-DATA.
Unionbank, L & P Food, and Town Square Magazine submitted the names of
those people who will be using the system from their respective sites.
These are the only people who will be able to log in from their site
and charge to their assigned account. The manager at Correct Data
also planned expiration dates for each customer account.

6-5
CREATING ACCOUNTS
CREATING ACCOUNTS

SAMPLE COMPANY: Correct Data
TYPE OF BUSINESS: Timesharing House
PRIMARY MODE OF OPERATION: Batch

_____________________________________

ACCOUNT CORRECT-DATA
USER Hudson, Holland, Gerard, Gionet, King, Kelly, Kohn
(Note: These 7 people are all the users at Correct Data)

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

ACCOUNT UNIONBANK
USER Warriner, Bloomstran, Prest, Pendergast
EXPIRES June 1, 1986

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

ACCOUNT LP-FOOD
USER Schied, Queeny, Smith
EXPIRES July 1, 1986

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

ACCOUNT TOWN-SQUARE
USER Markley, Gerhard, Dole
EXPIRES July 15, 1986

Figure 6-1: Accounting Scheme 1
Figure 6-1: Accounting Scheme 1

Using the same sample company, Figure 6-2 shows how a simple
accounting scheme of this type can be expanded into a form of project
administration. Here, Correct Data and one of its customers,
Unionbank, broke down the base accounts into subaccounts.

Because Correct Data bills Unionbank for all its computer usage as one
account, the manager at Correct Data is not concerned with how
Unionbank subdivides its account, and is probably not aware of the
subaccounts at Unionbank. The manager at Unionbank, however, is
concerned with the computer usage costs incurred by each department
within his company. He supplies Correct Data with the name of the
file that contains his subaccount information.

6-6
CREATING ACCOUNTS
CREATING ACCOUNTS

SAMPLE COMPANY: Correct Data
TYPE OF BUSINESS: Timesharing House
PRIMARY MODE OF OPERATION: Batch

_____________________________________________

ACCOUNT CORRECT-DATA
USER Hudson, Holland

SUBACCOUNT PAYROLL
USER Gerard, Kelly

SUBACCOUNT OVERHEAD
USER Gionet, Kohn, Kelly
EXPIRES December 31, 1986

SUBACCOUNT PROGRAMMING
USER King, Carlson

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

ACCOUNT UNIONBANK
USER Warriner

SUBACCOUNT TRUST
USER Bloomstran

SUBACCOUNT LOANS
USER Prest

SUBACCOUNT MSTRCHG
USER Prest, Pendergast

SUBACCOUNT PAYROLL
USER Bloomstran

Figure 6-2: Accounting Scheme 2
Figure 6-2: Accounting Scheme 2

Section 6.3 describes how to enter the information for Figures 6-1 and
6-2 into files that are used to create an account data base.

6.3 CREATING AN ACCOUNT DATA BASE
6.3 CREATING AN ACCOUNT DATA BASE

Sections 6.3.1 through 6.3.3 describe how to use your selected
accounting scheme and create the necessary files for your data base.
Specifically, these sections include how to enter accounting data into
files, how to run the account generator program (ACTGEN) to create the
data base, and what to do if an error occurs.

6-7
CREATING ACCOUNTS
CREATING ACCOUNTS

6.3.1 Entering Accounting Data into Files
6.3.1 Entering Accounting Data into Files

Base and subaccount files are created using a text editor. The format
below shows the combination of entries you can make in accounting
files using the CREATE command. Each file you or a project
administrator creates can contain one or more accounts. Each account
can point to one subaccount file, where additional account information
is stored pertaining to that account. Following the format is a
summary of the valid commands in an account file.

ACCOUNT DATA FILE FORMAT

______ _____________________________
@CREATE (FILE) filename.type
INPUT: filename.type.1

_______ _______________________________________________
00100 ACCOUNT account/SUBACCOUNT:dev:filename.type-
_______________________
00200 /CLASS:n/ALLOW:n,n
____ _______________________
00300 USER name,name,name,...
_________ ____________________
00400 DIRECTORY dev:
_____ ______________ _____ ___________
00500 GROUP (ON STRUCTURE) dev:/USER:user group number
_____ ___ __________ ________________________ _____ ___________
00600 GROUP (ON STRUCTURE) dev:/DIRECTORY:directory group number
_____
00700
_______
*EU

In addition to the above entries, each entry in the file can have an
expiration date in the form:

/EXPIRES:dd-mm-yy hh:mm

This switch indicates when the account will no longer be valid for
that entry in the file. For example:

USER name1,name2/EXPIRES:10-JAN-86,name3,name4

In the above example, name2 can no longer use this account after 10
January 1986. Name1, name3, and name4, however, can continue to use
the account beyond that date. You could also place the switch
immediately following the USER entry. For example:

USER/EXPIRES:10-JAN-86, name1, name2, name3, name4

This format specifies that none of the users in the list can use the
account after a certain date. The account, however, remains open, and
you can place another list of users in the file who can use the
account.

Table 6-1 summarizes the account data file commands. You can type the
entire command, or just the characters necessary to distinguish one
command from another. For example, ACCOUNT can be typed as AC.

6-8
CREATING ACCOUNTS
CREATING ACCOUNTS

Because the ACCOUNT command has several modifiers, you may have to
continue typing the modifiers on the next line. To do this, use a
hyphen at the end of the line and continue typing the ACCOUNT
modifiers on the next line. For example,

_______ ___________________________ ____________
0100 ACCOUNT TEST/SUBACCOUNT:SYSA: ACCOUNT.TXT-
__________________
0200 /CLASS:2/ALLOW:1,3

Table 6-1: Summary of Account Data File Commands
Table 6-1: Summary of Account Data File Commands

__________________________________________________________________

Command Description
Command Description
__________________________________________________________________

ACCOUNT Specifies the name of the account that you or
a project administrator wish to assign.

Note: The ACCOUNT command must be the first
entry in an account data file because all
subsequent entries up to the next ACCOUNT
entry are modifiers.

/SUBACCOUNT: Modifies the ACCOUNT command. It includes the
specification of the file where additional
data for the account can be found.

Note: The ACCOUNT command accepts only one
/SUBACCOUNT:modifier.

Example: One of your accounting files
contains the following commands.

ACCOUNT CORRECT-DATA/SUBACCOUNT:
ACCT.TXT
ACCOUNT UNIONBANK/SUBACCOUNT:
ACCTG.TXT

ACTGEN looks in ACCT.TXT for more
account data for the account CORRECT-DATA,
and it looks in ACCTG.TXT for more
data for account UNIONBANK.

6-9
CREATING ACCOUNTS
CREATING ACCOUNTS

Table 6-1: Summary of Account Data File Commands (Cont.)
Table 6-1: Summary of Account Data File Commands (Cont.)

Command Description
Command Description

/CLASS:n Modifies the ACCOUNT command and is used in
conjunction with the class scheduler. It
specifies the scheduling class that is valid
for this account. For example,

ACCOUNT CHEM-207/CLASS:3

means that class 3 is valid when using the
account CHEM-207. ACTGEN places this
information in the system's accounting data
base for use by the class scheduling
routines. Use the /CLASS:n switch only if you
have selected to specify class scheduling by
account. (Refer to Section 10.1 for a
complete description of using the class
scheduler by account.)

When a user gives an account that does not
have a valid class associated with it, the
system uses the default class, class 0. If
the account has a class associated with it,
that class is used. The percentage of CPU
time that classes can receive is defined in
the n-CONFIG.CMD file.

To use class scheduling by account, you must
have:

o made the appropriate entries in the
n-CONFIG.CMD file.

o updated your ACCOUNTS.CMD file (and
subaccount files) to specify the classes
that are associated with each account.

o run ACTGEN with the INSTALL command to
update the ACCOUNTS-TABLE.BIN file.

o given the ENABLE CLASS-SCHEDULER command
to OPR or brought the system down and back
up again to start class scheduling.

6-10
CREATING ACCOUNTS
CREATING ACCOUNTS

Table 6-1: Summary of Account Data File Commands (Cont.)
Table 6-1: Summary of Account Data File Commands (Cont.)

Command Description
Command Description

/ALLOW:n,n Modifies the ACCOUNT command and is used in
conjunction with the class scheduler. It
allows you to delegate the assigning of
classes to subaccounts by project
administrators. It specifies the class or
classes that can be used by subaccounts of
this account. For example,

ACCOUNT CHEM/SUBACCOUNT:MORE.TXT-
/CLASS:2/ALLOW:1,3

means the CHEM account is in class 2, and
that subaccounts created under CHEM can be in
either class 1 or class 3. If no /ALLOW
switch is given, the administrator is not
restricted to using certain classes and,
therefore, can give the subaccounts any
class. For example, the administrator can
give them the same class as the superior
directory. The /ALLOW switch is useful when
you want the superior account to be in
perhaps a higher percentage class than its
inferior accounts. Remember that if the
administrator does not give a /CLASS switch
to the subaccount, users who log into or
change to this subaccount will be in class 0.

USER Specifies one user or the list of users who
are allowed to use this account.

* Specifies that an account is valid for all
users on a system. The * is a special
argument to the USER command.

Example: One instance when you might use * is
if you have not established an accounting
scheme but would like to allow users to log
into the system. You could set up one account
and use the * to indicate that all users can
use that account.

You could also use the * as follows:

ACCOUNT MATH-101
USER: MATH.*

6-11
CREATING ACCOUNTS
CREATING ACCOUNTS

Table 6-1: Summary of Account Data File Commands (Cont.)
Table 6-1: Summary of Account Data File Commands (Cont.)

Command Description
Command Description

This means that all users with a user name
beginning with MATH can use the MATH-101
account. For example, the users assigned the
user names MATH.SMITH, MATH.JONES, and
MATH.BROWN can all use this account.

DIRECTORY Specifies a directory name. It indicates that
the account is valid for anyone with write
access to the directory. This feature allows
users to create or store files in systemwide
or groupwide directories and to charge them
to an "overhead" account different from their
own account. The usage charged to this
directory could be absorbed by system or
project administration. This command also
prevents users from being charged for file
storage in files-only directories.

Note: The DIRECTORY command also accepts a
form of the wildcard entry. The valid forms
are: *:<*>, dev:<*>, or *:. The asterisk
indicates that users with write access to any
of the directories matching the wildcard
entry may charge their file creation to a
certain account.

Example: The file that contains account data
for account CORRECT-DATA.UNIONBANK.FUND has
the entry:

DIRECTORY PS:

This entry means that anyone with write
access to directory can use the
account CORRECT-DATA.UNIONBANK.FUND when
storing files there.

6-12
CREATING ACCOUNTS
CREATING ACCOUNTS

Table 6-1: Summary of Account Data File Commands (Cont.)
Table 6-1: Summary of Account Data File Commands (Cont.)

Command Description
Command Description

GROUP Specifies that an account is valid for use by
certain user and directory groups on a
structure. (Refer to Section 5.8 for a
description of groups.)

/USER:nnn Modifies the GROUP command and can be used in
/DIRECTORY:nnn any combination. (nnn is a decimal user or
directory group number.) /EXPIRES: can be
placed after either modifier to indicate when
an account becomes invalid for use by the
group.

Note: Using the GROUP command is helpful if
many people are eligible to use an account.
Specifying their group number (if they are in
a group) eliminates typing a long list of
names incorrectly.
__________________________________________________________________

6-13
CREATING ACCOUNTS
CREATING ACCOUNTS

6.3.2 Sample Data Files
6.3.2 Sample Data Files

The examples below show how you could enter the information in Figures
6-1 and 6-2 into account data files. The first example shows the data
file for Figure 6-1. Tabs and comment lines beginning with an
exclamation point (!) can be used within the file for ease in reading
or formatting the file. This file in particular contains all the base
accounts and should be stored in your directory. You may find it
easier when you run ACTGEN if you name the file
ACCOUNTS.CMD. ACCOUNTS.CMD is the default file that the TAKE command
under ACTGEN looks for. (Refer to Section 6.3.3 for running ACTGEN
and giving the TAKE command.)

______ _________________________
@CREATE (FILE) ACCOUNTS.CMD
Input: ACCOUNTS.CMD.1

NOTE

Lines 300 and 400 contain all the users at Correct
Data. However, you would not use the asterisk (*)
because it would enable all the users of the system,
including the users at Unionbank, L & P Food, and Town
Square to charge to the CORRECT-DATA account.

Figures 6-3 and 6-4 show what information to enter into base and
subaccount files for Figure 6-2. Each block in Figures 6-3 and 6-4
contains information to be entered into a separate file. Some of the
blocks contain subaccount (/SUB:) entries that point to other files
containing more information about that particular account.

6-14
CREATING ACCOUNTS
CREATING ACCOUNTS

Figure 6-3 shows which entries to make for account CORRECT-DATA and
its subaccounts (the top half of Figure 6-2.)

Figure 6-4 shows which entries to make for account UNIONBANK and its
subaccounts (the bottom half of Figure 6-2.) Note that all the base
account entries for both Correct Data and Unionbank are contained in
the file ACCOUNTS.CMD.

Figure 6-3: Correct-Data Accounting Files
Figure 6-3: Correct-Data Accounting Files

The accounts that will be created are:

CORRECT-DATA.PAYROLL
CORRECT-DATA.OVERHEAD
CORRECT-DATA.PROGRAMMING

Note that users Hudson and Holland can use any account number that
begins with CORRECT-DATA, but user Gerard can use only the account
CORRECT-DATA.PAYROLL. User Kelly can use the accounts
CORRECT-DATA.PAYROLL and CORRECT-DATA.OVERHEAD.

The file type for account data files is optional. Your project
administrators can use any file type, for example, .TXT, .CMD, or
.ABC.

6-15
CREATING ACCOUNTS
CREATING ACCOUNTS

Figure 6-4: Unionbank Accounting Files
Figure 6-4: Unionbank Accounting Files

6-16
CREATING ACCOUNTS
CREATING ACCOUNTS

The accounts that will be created are:

CORRECT-DATA.UNIONBANK.TRUST
CORRECT-DATA.UNIONBANK.PAYROLL
CORRECT-DATA.UNIONBANK.MSTRCHG
CORRECT-DATA.UNIONBANK.LOANS.INSTAL
CORRECT-DATA.UNIONBANK.LOANS.CORP
CORRECT-DATA.UNIONBANK.LOANS.COMM

6.3.3 Running the ACTGEN Program
6.3.3 Running the ACTGEN Program

After you create the base account files and the project administrator
notifies you that all his subaccount files are complete, you can tell
the operator to run the ACTGEN program. ACTGEN takes the accounting
information in these files and creates an account validation data
base. It is through this data base that the monitor validates all
accounts entered by the users of your system. ACTGEN is a privileged
program, so you must enable WHEEL or OPERATOR capabilities before
giving the ACTGEN command. The command appears as follows:

______ _____
@ENABLE (CAPABILITIES)
___________
$ACTGEN
ACTGEN>

Valid commands that can be given to ACTGEN are HELP, EXIT, TAKE,
CTRL/A, and INSTALL.

The HELP command lists information to assist you when running the
ACTGEN program.

The EXIT command terminates the program and returns you to the TOPS-20
command level ($).

The TAKE command accepts as its argument either a file specification
or a carriage return. A carriage return defaults to your connected
directory and the filename ACCOUNTS.CMD. If you do not name your base
account file ACCOUNTS.CMD, the file you specify should be the one that
contains your base account information and points to all the existing
subaccount files. The TAKE command tells ACTGEN to look in the
specified (or default) file for account information. It also tells
ACTGEN to look at any subaccount file specifications for additional
information pertaining to the account(s) in the base account file.
Using Figures 6-1 and 6-2, the manager, Hudson, would specify the TAKE
command as follows:

______ _____
@ENABLE (CAPABILITIES)
___________
$ACTGEN
____ _____
ACTGEN> TAKE (COMMANDS FROM FILE)

6-17
CREATING ACCOUNTS
CREATING ACCOUNTS

If the manager in these examples had named his base account file
MACCT.TXT, he would specify the TAKE command as follows:

____ ______________________
ACTGEN> TAKE (COMMANDS FROM FILE) MACCT.TXT

CAUTION

If the data files that are pointed to by your base
account file are located on structures other than the
system structure, be sure the required structures are
mounted. Otherwise, the ACTGEN program will fail on
those accounts that have subaccount files on unmounted
structures.

ACTGEN takes all the information specified in the account files, forms
the valid accounts, and creates a new version of the file
ACCOUNTS-TABLE.BIN in the directory where ACTGEN is running. Each
time the ACTGEN program is run successfully, a new version of this
file is created.

While ACTGEN is creating the data base file, it checks for duplicate
entries, e.g., two accounts of the same name, and the length of the
accounts. If an error occurs, an appropriate message is printed on
the terminal where ACTGEN is running, but the program continues to
build the data base, using only the accurate data. You should make a
note of the error on an error log sheet that you have prepared and
later correct the appropriate files using an editor.

ACTGEN also checks expiration dates. If two or more expiration dates
are given for the same entry in a file, the system uses the earliest
date. For example: if you specify May 15, 1987 as the expiration
date for account MATH and your project administrator specifies August
30, 1987 for the account MATH.LAB-201, the system will stop validating
all accounts beginning with MATH as of May 15, 1987.

You can press CTRL/A while ACTGEN is running to stop the program and
return to ACTGEN command level. The data files are closed and no new
version of the data base file ACCOUNTS-TABLE.BIN is created from this
session.

The INSTALL command starts account validation. When you enter this
command, ACTGEN copies the ACCOUNTS-TABLE.BIN file in your connected
directory (or the directory where ACTGEN created the file) to
ACCOUNTS-TABLE.BIN on the system structure and enables account
validation using this new data base.

Because the new version of ACCOUNTS-TABLE.BIN is kept in the directory
where ACTGEN was run and not in the directory , you have a
means of correcting any errors that might occur without disturbing the
version currently running in the ACCOUNTS-TABLE.BIN file on
the system structure. You can give the INSTALL command after you have
corrected any problems.

6-18
CREATING ACCOUNTS
CREATING ACCOUNTS

If you do not receive any errors while ACTGEN is creating the data
base file (ACTGEN has successfully completed the accounting file and
you receive the ACTGEN prompt), you can give the INSTALL command
immediately.

You should keep track of which version of the
ACCOUNTS-TABLE.BIN file you are using. A log book that
contains the date that ACTGEN was run and the version number of the
data base file is helpful should a system problem occur and you are
not sure of which data base file you were using. To find out which
version you are using, enable capabilities and give the DIRECTORY
command for ACCOUNTS-TABLE.BIN on the system structure. The
generation number indicates the version that is presently running.
The system looks in the current data base file each time it validates
a given account.

6.3.4 Data Base Failures/Recovery
6.3.4 Data Base Failures/Recovery

If your accounting files were set up inaccurately, or you entered
random incorrect data into the data base file, account validation will
not work properly. You are aware of this because users cannot log in
and/or use accounts that are normally valid for them. Therefore, the
account OPERATOR is set up for the user OPERATOR and is always valid.
The operator can log into with the OPERATOR account, fix
the files that are in error, and run ACTGEN to get account validation
working again.

6.4 VALIDATING ACCOUNTS
6.4 VALIDATING ACCOUNTS

An account is validated when a user gives any one of the following
TOPS-20 commands.

o LOGIN - A user must have a valid account to successfully log
into the system

o SET ACCOUNT (TO) argument

o Any queue commands, for example, PRINT, SUBMIT, if the
account is different from the currently validated account

o SET FILE ACCOUNT (OF FILES) arguments (TO) argument

o File creation with an explicit account

6-19
CREATING ACCOUNTS
CREATING ACCOUNTS

The system records the computer time used for valid accounts. This
includes CPU time, time used per structure,[1] and peripherals used
per job, that is, the number of pages printed on the line printer,
tape mounts, tape records read/written, card reader usage, and disk
storage. The computer usage incurred by each account is stored in the
accounting USAGE.OUT file. This file is used for reports and billing.
_______ _____ ____ _____________
(Refer to the TOPS-20 Usage File Specification for information about
reading and using this file).

How often you run ACTGEN and create a new data base file depends on
how frequently you change your accounts. If you expect to have
frequent changes (e.g., opening and closing accounts), you may want to
establish a standard time each week to run ACTGEN. Your
administrators should inform the operator when changes are made to
their subaccount files.

NOTE

Once ACTGEN is run and the data base file has been
created, you can dump all the account files to
magnetic tape and conserve some of your disk space.
You must copy the files to disk the next time you need
to run the ACTGEN program.

---------------

[1] To account for the time used on a structure, you must set the
_______ __________ _____
structure as REGULATED. Refer to the TOPS-20 Operator's Guide
for a description of REGULATED and NONREGULATED structures.

6-20

CHAPTER 7
CHAPTER 7

SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

All the disk packs on your system must be backed up on magnetic tape.
This procedure provides both a permanent record of the contents of the
disk and a precautionary measure in the event a disk pack and/or its
contents are destroyed. On the first day of operation, start a system
backup procedure that includes:

1. Saving all the files in all the directories on all structures

2. Saving the directory parameters and critical system programs

3. Saving the front-end file system (one time only)

These procedures should become a part of the operator's scheduled
duties.

It is important to start backing up the system immediately after
installation. If you follow the backup procedures as they are
_______ __________ ______
outlined here and in the TOPS-20 Operator's Guide, you can restore the
file system quickly and easily should a mishap occur.

______
DUMPER

The following sections discuss using the DUMPER program to save files.
Make sure when you restore these files with DUMPER that you are
running the correct version of DUMPER with your TOPS-20 monitor and
that the tape version is compatible with the software. Otherwise,
directory passwords could become unusable and you may have to manually
respecify them with the BUILD command. Refer to Section 11.2,
Password Encryption, for details. In addition, project-programmer
numbers, supported in TOPS-20 Version 6, may not be restored at all
with incompatible versions of the software.

In a CFS configuration, DUMPER must run on the system to which the
tape drives are attached.

7-1
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

To simplify backup and restore operations, you can create DUMPER
command files for the operator. Rather than type a list of commands
to DUMPER, the operator can then just give the TAKE command with a
command file name as an argument. DUMPER will sequentially execute
commands contained in the file.

_______ ____ _________ _____ _______ __________ _____
The TOPS-20 User Utilities Guide and the TOPS-20 Operator's Guide
discuss the DUMPER program in detail.

7.1 SAVING ALL FILES IN ALL DIRECTORIES
7.1 SAVING ALL FILES IN ALL DIRECTORIES

Have the operator run the DUMPER program (with the /FULL-INCREMENTAL
switch to the SAVE command) to save all files in all directories.
This procedure includes saving all the directories on the system
structure and all the directories on any additional structures you
have created. You can save all the files (a full dump) or just the
files that have changed since the last time the operator ran DUMPER
(an incremental dump).

Start a library of the magnetic tapes from the DUMPER operations.
Each structure should be copied to a separate tape(s). Each tape
should be identified with the system model number or name, for
example, 2060, or System-A, the date, the type of save (full or
incremental), the name of the structure, and the tape number. (A tape
set name may replace the tape number, if labeled tapes are used.) A
typical identification may look like:

SYSTEM-A (2060) SYSTEM-A (2060)
30-JANUARY-1988 30-JANUARY-1988
Incremental OR: Full
ADMIN: ADMIN:
Tape #1 of 2 Tape #3 of 3

In addition to keeping the tapes, keep the listing of their contents.
(The operator includes a command to DUMPER to list the contents of the
magnetic tapes on the line printer.) These DUMPER log files can be
conveniently kept in a binder with the most recent listing on top.
Identify each binder with the system model or name, for example, 2065
or System-A. (Chapter 9, System Problems/Crashes describes how to use
these log files to restore directories and files.)

Tell users that backup files do exist and post the times when the
operator normally creates the backup tapes. Many system managers do
not allow users to enter the computer room to mount and use the tapes
themselves.

7-2
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

NOTE

____ ___
The DUMPER program DOES NOT save the files in the
console front-end file system. If you lose these
files, you must restore them from the floppy disks.
(Refer to Section 7.6)

7.1.1 Full Dumps
7.1.1 Full Dumps

Full dumps contain all the information on the system, with the
exception of the console front-end files, and can be used to restore
many of the files that were on the system to their previous state.
Therefore, full dumps contain a copy of every file in every directory
on every structure.

NOTE

Full dumps are known as FULL-INCREMENTAL dumps. This
name corresponds to the /FULL-INCREMENTAL switch that
you give with the SAVE command to DUMPER.

7.1.2 Incremental Dumps
7.1.2 Incremental Dumps

Incremental dumps (using the /INCREMENTAL switch with the SAVE
command) cause DUMPER to save the files that have never been saved
(new files) and the files that have been updated since the last time
an incremental DUMPER operation was performed. Many managers request
an incremental dump Monday through Thursday and a full dump on Friday.

The File Descriptor Block (FDB) of each file contains the information
necessary to determine if the file has been updated since it was last
saved during an incremental DUMPER operation. A file that has changed
since the last time it was saved is automatically saved again on tape;
otherwise, it is passed over.

The operator should give the INCREMENTAL switch to DUMPER and specify
each structure one at a time. By running DUMPER for each structure
individually, the operator can copy each structure onto a separate
tape. After running DUMPER and copying the structures that are
presently on-line, the operator should mount any additional structures
that have been used that day and run DUMPER for them also.

An incremental dump is faster than a full dump and requires less
magnetic tape. By specifying a value with the /INCREMENTAL switch,
you can cause modified files to be written to more than one
incremental backup tape. This is helpful if you want to be certain
you can recover the files, even if one of the tapes has data errors.

7-3
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

7.1.3 Security of Backup Tapes
7.1.3 Security of Backup Tapes

It is a good idea to protect the security of your backup tapes. If
you allow a non-privileged user to mount them, he or she may gain
access to confidential information, such as other user's data files.
If the unencrypted passwords were saved along with other directory
parameters, a technically sophisticated user can retrieve them from
the DUMPER backup tapes, and thus obtain unauthorized access to the
privileged accounts on the system.

7.2 A COMMON BACKUP POLICY
7.2 A COMMON BACKUP POLICY

A common backup policy is outlined below. You can set up your own
backup policy.

1. Each day, take an incremental save of the files that have
changed from the previous day's backup tape. Keep the
incremental saves until a full save is made, at which time
you can recycle the incremental tapes.

2. At the end of the week, take a full save of all the files on
the system. Keep the full saves for six months, at which
time you can recycle the tapes into the backup system.

3. Every six months, take a full save and keep it for a number
of years, or if you choose, indefinitely.

7.3 MAGNETIC TAPE REQUIREMENTS
7.3 MAGNETIC TAPE REQUIREMENTS

You need a supply of magnetic tapes to start a system backup
procedure. This section provides a guideline for the number of tapes
you should have on hand for your installation. It is assumed that
there are 2400 feet per reel of tape.

7-4
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

__________________________________________________________________

Type of Reels Per Bits Per
Type of Reels Per Bits Per
Disk Drive Drive Inch
Disk Drive Drive Inch
__________________________________________________________________

RP06 7 1600

RP06 2 6250

RA60 9 1600

RA60 3 6250

RP20 (one 19 1600
spindle)

RP20 (both 37 1600
spindles)

RP20 (one 6 6250
spindle)

RP20 (both 12 6250
spindles)

RP07 7 6250

RP07 19 1600

RA81 6 6250

RA81 19 1600
__________________________________________________________________

Therefore, the number of tapes you stock depends on the type of disks
at your installation. It also depends on the backup procedure you
use. For example, if you save your daily incremental tape dumps for a
longer time than usual, it takes longer to recycle these tapes into
the backup system, and thus you need more tapes.

Generally, during the first month after installation, you may need
approximately 36 (2400 ft.) tapes for each RP06 or RA60, 45 tapes
(6250 bit/in) or 180 tapes (1600 bit/in) for each RP20 disk (2
spindles), and 72 tapes for each RP07 or RA81 (1600 bit/in).

7-5
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

NOTE

These estimates assume a magnetic tape blocking factor
of 1. You can specify a higher blocking factor and
save much space on your tapes. Before doing this,
however, there are cautions that you must consider.
_______ ____
The description of DUMPER in the TOPS-20 User
_________ _____
Utilities Guide explains how and when you can increase
blocking factors.

7.4 MAKING A SYSTEM CRASH TAPE
7.4 MAKING A SYSTEM CRASH TAPE

As the name implies, the system crash tape is used to re-create the
system structure should it become unusable. This tape is created in
addition to the tapes that contain FULL-INCREMENTAL and INCREMENTAL
saves of all files and directories. You should make a new system
crash tape whenever you add a new user, change any directory
parameters, or make a change (patch) to:

o The monitor you are running

o The TOPS-20 Command Processor

o The DLUSER program

o The DUMPER program

Therefore, the crash tape contains only the files necessary to recover
user directory parameters and important system programs. User files
themselves are restored from the FULL-INCREMENTAL and INCREMENTAL
saves of the public structure.

Label this tape SYSTEM BACKUP TAPE and include the system structure
name; DECSYSTEM-20 model number or name, for example, 2060 or
System-B; and the date and time the tape was created. You should
follow this procedure once a day if users are allowed to change their
own directory parameters. (Refer to Section 5.7.2 for information
about allowing users to change directory parameters.) If you are not
using password encryption (refer to Section 11.2), be careful to
protect the backup tapes against reading by unauthorized users,
because all the passwords for your users will be accessible.

If you are also using mountable structures, you should periodically
run DLUSER to copy their directory parameters to a file on another
structure, preferably the system structure. Then, if the mountable
structure is destroyed, you will be able to recreate the directories.

7-6
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

NOTE

Do not use a labeled tape when creating a System Crash
Tape. The reason for this is that the installation
software that is used to create the system structure
cannot read tape labels.

The order of files on the crash tape is:

1. MONITR.EXE

2. EXEC.EXE

3. DLUSER.EXE

4. DLUSER data files

5. DUMPER.EXE

6. DUMPER save sets containing the directories:

Notice that the format of this tape is the same as the TOPS-20
Installation Tape that you used to install the TOPS-20 software.

7-7
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

7.5 MAKING A CRASH TAPE USING BATCH
7.5 MAKING A CRASH TAPE USING BATCH

You can create a batch job to make your crash tape or type the
commands at the operator's terminal. Example 1 shows the standard
control file that you can submit as a batch job to create this tape.
In the example, PUB: is the name of the system structure.

EXAMPLE 1

SYSTAP Control File

____ ___________________
@TYPE(FILE) SYS:SYSTAP.CTL

! Obtain a tape drive
@MOUNT TAPE TAPE:/WRITE/LABEL:UNLABELED

!Systems not using Tape Drive Allocation must replace the
!MOUNT TAPE command with @ASSIGN MTA0: and @DEFINE TAPE:
!(AS) MTA0: commands.

@ENABLE (CAPABILITIES)
@REWIND (DEVICE) TAPE:

!Save the monitor
@GET (PROGRAM) PUB:MONITR.EXE
@SAVE (ON FILE) TAPE: !Save the TOPS-20 Command Language Interpreter
@GET (PROGRAM) SYSTEM:EXEC.EXE
@SAVE (ON FILE) TAPE:

!Save the DLUSER program
@GET (PROGRAM) SYS:DLUSER.EXE
@SAVE (ON FILE) TAPE:

!Run the same DLUSER program, saving the directory structure
!on tape
@START
*DUMP (TO FILE) TAPE:
*EXIT

!Save DUMPER
@GET (PROGRAM) SYS:DUMPER.EXE
@SAVE (ON FILE) TAPE: !Run the same DUMPER, saving SYSTEM: and SYS:
@START
*TAPE (DEVICE) TAPE:
*LIST (LOG INFORMATION ON FILE) SYSTAP.LPT
*SSNAME SYSTEM-FILES
*SAVE (DISK FILES) PUB:,PUB:
*SSNAME SUBSYS-FILES
*SAVE (DISK FILES) PUB:,PUB:
*EXIT

7-8
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

!Print the DUMPER log file
@PRINT SYSTAP.LPT/NOTE:BACKUP TAPE

@DISMOUNT TAPE:
@

!Systems not using Tape Drive Allocation must replace the
!DISMOUNT TAPE: command with @UNLOAD (DEVICE) TAPE: and
!@DEASSIGN TAPE: commands.

To run SYSTAP, submit the batch control file using the TOPS-20 SUBMIT
command. In the event the system structure becomes unusable, the
crash tape can now be used by following the instructions in the
_______ __ _____ _ ____________ _____
TOPS-20 KL Model B Installation Guide.

HINT:

Before you store the crash tape, verify that you have
made a usable tape. That is, mount the new crash
_______ __ _____
tape, follow the instructions in the TOPS-20 KL Model
_ ____________ _____
B Installation Guide to load the monitor, and use
DUMPER to get a listing of the tape's contents.

7-9
SYSTEM BACKUP PROCEDURES
SYSTEM BACKUP PROCEDURES

7.6 SAVING THE CONSOLE FRONT-END FILE SYSTEM
7.6 SAVING THE CONSOLE FRONT-END FILE SYSTEM

The DUMPER program does not save the contents of the console front-end
file system. You can, however, make a backup copy of the file system
by copying your floppy disks using the front-end program COP (for
copy). You should make at least one backup copy of your console
front-end file system (refer to Section 3.4).

To run the COP program, follow the steps outlined below. You need not
stop timesharing when following these steps.

1. At the operator's console, type CTRL/backslash; the system
prints PAR>.

______________
CTRL/backslash

PAR>

2. Type MCR COP and press the RETURN key; the system prints the
COP prompt.

___ ________
PAR>MCR COP
COP>

3. Place the floppy disk to be copied in drive 0 and the floppy
to contain the new files in drive 1. Be sure to mount the
floppy disks correctly; this includes checking that the paper
containing the floppy directory is not accidentally attached
to the back of the floppy disk.

4. Type DX1:=DX0: and press the RETURN key; the system starts
the copying, which takes a few minutes. After the copying is
complete, the system verifies the copy and prints a message.
Type CTRL/Z to exit COP.

______________
COP>DX1:=DX0:
COP - STARTING VERIFY

__
COP>^Z

5. To return to TOPS-20 Command Level, type a CTRL/backslash;
the system prints PAR>; type another CTRL/Z, or type QUIT and
press the RETURN key.

______________
CTRL/backslash

__
PAR>^Z

7-10

CHAPTER 8
CHAPTER 8

TAPE STORAGE
TAPE STORAGE

Chapters 1 through 6 deal primarily with setting up and using your
disk resources. Chapter 7, System Backup, describes how to save all
the data from your disk structures onto magnetic tape. These tapes
are the backup tapes that you use to restore directories and perhaps
entire disk structures if something happens to the disks (refer to
Chapter 9). In addition to using magnetic tapes for system backup
tapes, you can use magnetic tapes to store other types of data and
save valuable disk space.

This chapter describes two other uses for magnetic tapes, File
Archiving and File Migration. It also describes how you can allow the
system and the operator to control all tape drive assignments, Tape
Drive Allocation, and how you can set up some or all of your tapes to
contain labels, Tape Labeling. These uses are described in the
following order.

o FILE ARCHIVING

o FILE MIGRATION

o TAPE DRIVE ALLOCATION

o TAPE LABELING

In addition, the last section of the chapter discusses how to set up
two DECSYSTEM-20s to share a TX02 tape subsystem.

File archiving provides you and users of the system with a voluntary
way to move important files from the disk to magnetic tape for
long-term storage. These tapes are stored separately from your system
backup tapes. Users can access these tape files as easily as they
access files on the disk. When users want to restore archived files
to disk, they give a command to the TOPS-20 command processor. The
system then tells the operator which tapes to mount and proceeds to
restore the files. Section 8.1 describes why you would use the file
archiving facility, and how to set up your system to archive files to
magnetic tape.

8-1
TAPE STORAGE
TAPE STORAGE

File migration provides you with a means of controlling the use of
disk space. File migration is especially useful if your disk space is
very low on a particular structure, for example, the system structure.
This type of disk space control is, for the most part, involuntary on
the part of the user. Old unused disk files are periodically moved
(migrated) to magnetic tape by the system operator. Again, you should
store these tapes separately from your system backup tapes. Users
still maintain easy access to these files and retrieve them the same
way as they retrieve archived files. Section 8.2 describes why and
when you would use the file migration facility and how to set up your
system to migrate files to magnetic tape.

If you use the file archiving or file migration facilities, or both,
remember that these tapes are in addition to your system backup tapes.
They are not replacements. You must continue to run the DUMPER
program and create full and incremental system backup tapes.

Tape drive allocation provides the system and computer operator with
complete control over tape drive usage. This means that it prevents
users from issuing the ASSIGN command and reserving tape drives for
their jobs. When users issue the MOUNT command, the TOPS-20 Tape
Drive Allocation system and the operator control the allocation of
tape drives. You must use the tape drive allocation facility if you
use tape labeling; however, using tape drive allocation does not
restrict you to using labeled tapes.

Tape labeling provides a means of storing label information on the
tape itself that identifies the tape and describes the data on the
tape. This label information is in an industry standard format so you
can read and write tapes to be used with different computers. Tape
labels can also add more security and reliability to your tape system.
Section 8.4 describes why you would use tape labels, and also how to
set up your system to begin labeling tapes.

There are no dependencies among file archiving, file migration, and
tape labeling. For example, you can use the file archiving facility
without using file migration or tape labeling. Each tape facility can
be used separately. There is, however, the dependency that tape drive
allocation must be turned on to use tape labels.

8.1 FILE ARCHIVING
8.1 FILE ARCHIVING

File archiving provides a means of storing data on magnetic tape and
freeing valuable disk space. This type of off-line storage allows
users to store (archive) important files on tape, keeping their disk
space below their permanent allocation, and still have easy access to
those files.

If your installation has more than one computer system, the archive
tapes can be common to all systems. You can put files on tape from

8-2
TAPE STORAGE
TAPE STORAGE

one system, move a directory and its files to another system, and
still retrieve files from the tape in the ordinary manner.

Unlike general system backup tapes, the tapes that contain archived
files are usually kept for a much longer time, for example, seven to
ten years.

8.1.1 Setting Up the System to Use File Archiving
8.1.1 Setting Up the System to Use File Archiving

When you receive the TOPS-20 Installation Tape and have brought up the
TOPS-20 monitor, your system contains a built-in default of 3650 days
for recycling archived tapes. To change the 3650 day (10 year)
default, you can enter a command in the n-CONFIG.CMD file. The
command you use is:

ARCHIVE-TAPE-RECYCLE-PERIOD days

Select a length of time that is appropriate for your installation.
Place the ARCHIVE-TAPE-RECYCLE-PERIOD command in the n-CONFIG.CMD file
during software installation, or edit the file at a later date when
you are planning to reload the system.

Each time the DUMPER program copies an archived file to tape, it
places the expiration date argument in the FDB of the file. The MAIL
program notifies users when a file on tape has reached its expiration
date. If the file is no longer needed, the user can discard (using
the DISCARD command) the information in the file's FDB that points to
the file on tape. After all the files on a tape have passed their
expiration dates and no users have FDBs in their directories that
point to that tape, the tape can be recycled. Refer to Section 8.2.5
for additional information on how to recycle tapes.

8.1.2 What Happens When Users Archive Files
8.1.2 What Happens When Users Archive Files

Users archive files voluntarily by giving the ARCHIVE command. After
a specific generation of a file has been archived (e.g.,
MYFILE.CBL.6), it cannot change. Users can obtain copies of archived
files by using the RETRIEVE command, but cannot alter those files.
_______ ______ _____
The TOPS-20 User's Guide describes the ARCHIVE and RETRIEVE commands.

8-3
TAPE STORAGE
TAPE STORAGE

When you establish your installation's policy for file archiving and
notify users of its availability, you may want to instruct users to
archive source files only. For example, files with a file type

.CBL, .MAC, .TXT, .RNO, or .FOR

should be archived; but, files with the file type

.REL, .EXE, or .MEM

should not be. This restriction saves space on your magnetic tapes.

To completely archive a file, two copies must exist in the archives.
This means that each archived file is stored on two tapes. Having the
archived file on two tapes provides you with a backup tape if later
you cannot retrieve a file off one of the tapes. The DUMPER program,
which is used to archive files, records both tape identifying numbers
in the FDBs of the files being archived.

The diagrams below illustrate what happens when a user archives a
file.

First, the user creates a file. The File Descriptor Block (FDB),
among other file information, contains a pointer to the location of
the file on the disk.

Pointer to File
FDB ---------------------------------> DISK
on the Disk

The user gives the ARCHIVE command for this file. The first or next
time the operator runs DUMPER with the ARCHIVE command, the system
locates all files that have been marked for archival by the ARCHIVE
command and copies these files to tape. The FDB now contains pointers
to the file on the disk and to the file on the tape.

-----------
| | Pointer to File on the Disk
| | ---------------------------------------------> DISK
| |
| FDB |
| |
| | Pointer to File on Tape
| | ---------------------------------------------> TAPE
-----------

8-4
TAPE STORAGE
TAPE STORAGE

The second or subsequent time the operator runs DUMPER with the
ARCHIVE command (remember that archived files are contained on two
tapes), DUMPER copies the file again to the second tape. DUMPER then
deletes the pointer to the location of the file on the disk. DUMPER
places another pointer in the file's FDB to the second tape that
contains the file and deletes the contents of the file on disk. After
a user archives a file, the file name no longer appears in the user's
directory list. The user must give the DIRECTORY command with the
ARCHIVE or INVISIBLE subcommand to see the file name.

-----------
| | ----------------------------------------> TAPE
| |
| FDB | Two Pointers to Tape
| |
| |
| | ----------------------------------------> TAPE
-----------

8.1.3 What Happens When Users Retrieve Files
8.1.3 What Happens When Users Retrieve Files

Users request files be returned to disk (retrieved) by using the
RETRIEVE command. When the operator runs DUMPER to process retrieval
requests, DUMPER notifies the operator of the second tape that
contains the file. If the file cannot be copied from the tape (e.g.,
the tape is bad), DUMPER notifies the operator of the first tape that
contains the file. When DUMPER returns a file to disk, the FDB of
that file now contains two pointers to tape and one to the disk. The
pointer to the file on the disk remains in the FDB until the file is
deleted from disk.

8.1.4 When to Create Archive Tapes
8.1.4 When to Create Archive Tapes

You can select how often the operator runs DUMPER to archive files.
However, running DUMPER (with the ARCHIVE command) every day before or
after your general system backup procedure is probably closest to your
present schedule.

The steps below provide an example of a typical procedure. These
steps assume that this is the first time you are archiving files.
Although you do not have to use this procedure, it is one that best
_______ __________ _____
utilizes your tape resources. (The TOPS-20 Operator's Guide describes
the procedure for running DUMPER with the ARCHIVE command.)

8-5
TAPE STORAGE
TAPE STORAGE

____ _________
Step Procedure

1. The operator runs DUMPER and performs the normal (incremental
or full) backup procedures for the entire system. (Refer to
Chapter 7, System Backup Procedures.)

2. The operator mounts a brand new tape (a tape that has been
initialized if you are using tape labels; refer to Section
8.4.3) to contain the archived files, for example, TAPE 1.

3. The operator runs DUMPER with the ARCHIVE command. DUMPER
locates all files marked for archival and copies them to tape.

4. The next evening (or the next time system backup is performed),
the operator mounts a brand new tape, e.g., TAPE 2. He does
NOT mount the tape used the first time.

5. The operator runs DUMPER with the ARCHIVE command. This time
DUMPER finishes the archival run of the previous night by
making a second copy of those files. In addition, DUMPER
locates all the files newly marked for archival and copies them
to tape for the first time.

6. The operator repeats this process every day until the tapes are
full.

7. For example, the third night, the operator mounts the first
tape, TAPE 1.

8. The operator runs DUMPER. DUMPER finishes the archival run of
the previous night by making a second copy of the previous
night's files. It also locates all the files newly marked for
archival and copies them to tape.

9. The fourth night, the operator mounts the second tape, TAPE 2.
Again, DUMPER finishes the archival run of the previous night
by making a second copy of those files. It also locates all
the files newly marked for archival and copies them to tape.

NOTE

DUMPER checks tapes for duplicate files. It does not
write both copies of the same file on the same tape.
If the wrong tape is mounted, DUMPER outputs an error
message.

8-6
TAPE STORAGE
TAPE STORAGE

8.1.5 Processing Retrieval Requests
8.1.5 Processing Retrieval Requests

When a user gives the RETRIEVE command to request an archived file,
the request is stored in a queue. You must establish a policy for how
often the operator should process the retrieval requests contained in
_______ __________ _____
the queue. (The TOPS-20 Operator's Guide describes how to process
retrieval requests.) If you have encouraged users to archive their
files, you should instruct the operator to process the request queue
frequently.

8.2 FILE MIGRATION
8.2 FILE MIGRATION

Some installations must control the use of disk space by periodically
migrating files to magnetic tape. This forced file migration allows
the management of an installation to move old unused disk files to a
less expensive storage medium. Similar to archived files, migrated
files are still easily accessible to the user. File migration also
allows you to keep users' directories below their permanent
allocation. (Refer to Section 5.5 for a description of permanent and
working storage allocations.)

Whether you use the file migration facility depends almost entirely on
your disk space resources. If users are archiving files regularly, if
their directories are usually below their allowed permanent disk
allocation, and your system is not continuously interrupted with "disk
space low" messages, you may choose not to migrate files. Otherwise,
if you are constantly receiving the [CAUTION - DISK SPACE LOW ON
structure name] message, you may want to forcibly migrate files from
the disk.

Sections 8.2.1 through 8.2.3 describe using file migration. They
include:

o the program you must run before migrating files to tape

o the command that can be placed in the n-CONFIG.CMD file to
change the default tape recycle period

o when to run the REAPER program that marks files for migration
and marks for deletion the contents of archived and/or
migrated files

o a sample of the REAPER.CMD file that you can use as a default
file to be read by the REAPER program

o when to run the DUMPER program that locates files marked for
migration and copies them to tape

8-7
TAPE STORAGE
TAPE STORAGE

o when to process retrieval requests for migrated files

o when to recycle migrated (and archived) tapes

8.2.1 Setting Up the System to Use File Migration
8.2.1 Setting Up the System to Use File Migration

When you receive the TOPS-20 Installation Tape and have brought up the
new TOPS-20 monitor, your system contains a built-in default of 180
days for recycling migrated tapes. This default is placed in the FDB
of each file as it is migrated to tape.

To change the 180-day default, you can enter a command in the
n-CONFIG.CMD file to inform the system when you plan to recycle your
migrated tapes. This command is:

TAPE-RECYCLE-PERIOD days

Select a length of time that is appropriate for your installation.
The default of 180 days, however, is a standard time period. You can
place the TAPE-RECYCLE-PERIOD command in the n-CONFIG.CMD file at the
_______ __ _____ _
time you install the system (refer to the TOPS-20 KL Model B
____________ _____
Installation Guide). Or, you can edit the n-CONFIG.CMD file at a
later date. Remember that if you edit the file at a later date, you
must reload the system to process the commands in the n-CONFIG.CMD
file.

CAUTION

If you decide to change the 180 day default, place the
TAPE-RECYCLE-PERIOD command with the new argument in
the n-CONFIG.CMD file and reload the system.
Otherwise, the default recycling period does not
change until the next system reload.

8.2.2 Using the REAPER Program
8.2.2 Using the REAPER Program

The REAPER program is the tool used to free disk space. It performs
the following functions:

o Marks for migration the files that have not been referenced
for a specified period of time

o Marks for deletion the disk contents of archived or migrated
files, either after they have been successfully copied to
tape, or after they have been returned to disk with the
RETRIEVE command, and have not been referenced for a
specified period of time

8-8
TAPE STORAGE
TAPE STORAGE

o Trims directories that are over permanent disk allocation by
marking files in those directories for migration

o Deletes (purges) the tape pointers in FDBs on the disk that
have reached their tape storage expiration date. That is,
the file's FDB will no longer contain a pointer to the
contents of the file on tape.

You can instruct the operator to run the REAPER program and perform
one, several, or all of these functions. The operator can give a list
of commands to REAPER or use the TAKE command with the default
argument SYSTEM:REAPER.CMD. After the system is installed, the
directory contains a default REAPER.CMD file. You can use
this file as it is or use an editor and change the default parameters.
The default SYSTEM:REAPER.CMD file appears similar to the following.

____ ______________________
$TYPE (FILENAME) SYSTEM:REAPER.CMD

!Sample REAPER policy file

!Directories not to be considered (specify the structure and
!directory)

SKIP PUB:,PUB:,PUB:,PUB:

PERIOD 60 !Specifies the age limit on
!files

MIGRATE !Migrate files older than PERIOD days

DELETE-CONTENTS !Delete the contents of
!unreferenced files older than
!PERIOD with tape backup

TRIM !Trim directories over perm allocation
!back to perm allocation

ORDER *.TMP,*.LST,*.REL !TAKE files in this order
!during TRIM

Note that the SKIP command includes a list of directories that are not
to be touched by the REAPER program. You can add other system or user
directories to this list. The list can contain approximately 75
directories. Be sure that the operator always includes this command
when running the REAPER program; otherwise, you may accidentally
migrate some very important files from the disk. You can use more
than one SKIP command to specify additional directories to be skipped,
rather than list them all in one command. That way, if there is an
error in processing one command, it will not affect the processing of
the other commands. This is especially useful when SKIP commands are
included in a file.

8-9
TAPE STORAGE
TAPE STORAGE

The REAPER program accepts the following commands.

BEGIN (Processing files)
DELETE-CONTENTS (Of old offline files)
EXIT (To monitor)
LIST (Output to file)
MIGRATE (Old files to offline storage)
ORDER (For trimming)
PERIOD (For migration)
| POLICY (does a TAKE on SYSTEM:REAPER.CMD)

PURGE (Expired FDBs from disk)
SCAN (Only)
SKIP (Directories)
TAKE (Commands from file)
TAPE (Check of tapes in use)
TRIM (Directories over allocation)

_______ __________ _____
The TOPS-20 Operator's Guide provides a complete description of all
the commands that can be given to the REAPER program or placed in the
REAPER.CMD file. Typically, you give a number of commands to REAPER,
one for each operation you want performed.

The availability of disk space determines how often you run the REAPER
program. If your disk space is low, you may want to run the REAPER
program daily to free up as much disk space as possible. Other
installations may run it once a month or less.

8.2.3 Using the DUMPER Program
8.2.3 Using the DUMPER Program

After the REAPER program marks files for migration, the operator runs
the DUMPER program to copy the files to tape. Similar to an archived
file, a migrated file is not completely migrated until two copies of
the file exist on magnetic tape. Section 8.1.4 describes a procedure
for copying archived files to tape. You can use this same procedure
for migrated files, by using the MIGRATE command instead of ARCHIVE.

If you use both the file archiving facility and the file migration
facility, do not merge archived and migrated files on the same tapes.
The expiration dates for migrated files differ greatly from the
expiration dates on archived files. If you put them on the same tape,
you will end up saving migrated files for approximately ten years and
use up all your tape resources very quickly.

8-10
TAPE STORAGE
TAPE STORAGE

8.2.4 Processing Retrieval Requests for Migrated Files
8.2.4 Processing Retrieval Requests for Migrated Files

When a user gives a DIRECTORY command, the files that have been
migrated to tape still appear in the directory list; however, each
file has a notation (;OFFLINE) beside the filename to indicate that
the file is contained on tape and not on the disk. The versions of
migrated files that have been copied to tape can be returned to disk,
and unlike archived files, they can be altered and/or renamed in the
ordinary manner. The user requests that a migrated file be returned
to disk with the RETRIEVE command. These requests are stored in the
same queue as archive requests until the operator processes the queue.
_______ __________ _____
The TOPS-20 Operator's Guide describes how to process retrieval
requests. Retrieval requests for migrated or archived files should be
processed frequently.

8.2.5 Recycling Migration (and Archive) Tapes
8.2.5 Recycling Migration (and Archive) Tapes

When all the migrated or archived files on a tape have passed their
expiration dates and all pointers to these files on the disk have been
deleted, you can recycle the tape.

The PURGE command to REAPER checks tape expiration dates and notifies
users by the MAIL program when migrated or archived files on tape are
about to expire. Users can retrieve the file to disk again or discard
the tape pointer on disk if they no longer need the file.

The operator can determine if a tape can be recycled by giving the
TAPE command to REAPER. If a tape is not mentioned in the TAPE output
list, this means that none of the disk structures that are on-line at
this time and specified to REAPER contain FDB pointers to that tape.
However, be sure that you check all possible places for on-line (disk)
pointers to this tape. That is, run REAPER with the TAPE command on
all the disk structures on all systems that may contain pointers to
this tape. If files have passed their expiration date and pointers to
them still exist on the disk, the operator can run REAPER with the
PURGE command to delete these pointers. The operator should be
certain that files are no longer needed before using the PURGE
command.

HINT

When a migration tape is full, have the operator use
the PRINT command to DUMPER to obtain a hard-copy
listing of the tape contents.

8-11
TAPE STORAGE
TAPE STORAGE

8.3 TAPE DRIVE ALLOCATION
8.3 TAPE DRIVE ALLOCATION

Tape drive allocation provides the system, and not the user, with
complete control over tape drive usage. When accessing a magnetic
tape, the user must give a MOUNT command to request that the operator
mount the tape on a drive. Once the operator responds to the user's
request, the user can access the tape. When the user is finished with
the tape, the user gives the DISMOUNT command to release the tape
drive back to the system. From the user's point of view, the MOUNT
and DISMOUNT commands replace the ASSIGN and DEASSIGN commands. The
operator selects the drive for the user, and the system informs the
user how to access the tape. Using tape labeling requires that you
use tape drive allocation; however, this does not restrict you to the
use of labeled tapes only.

8.3.1 When to Use Tape Drive Allocation
8.3.1 When to Use Tape Drive Allocation

Table 8-1 lists the differences between using and not using tape drive
allocation.

Table 8-1: Tape Drive Allocation
Table 8-1: Tape Drive Allocation

__________________________________________________________________

Tape Drive Allocation No Tape Drive Allocation
Tape Drive Allocation No Tape Drive Allocation
__________________________________________________________________

You must make an entry in No entry required in the
the n-CONFIG.CMD file to n-CONFIG.CMD file.
use tape drive allocation.

Users can use labeled and No support for labeled tapes. This
unlabeled tapes. means that all tapes, whether they
contain labels or not, are treated
as unlabeled.

Users cannot give the Users can give the ASSIGN and
ASSIGN and DEASSIGN DEASSIGN commands for allocated tape
commands for allocated tape drives and cannot use the MOUNT and
drives, but must give the DISMOUNT commands.
MOUNT and DISMOUNT
commands.

The operator should not use The operator may unload tapes using
the UNLOAD button on tape the UNLOAD button on the tape drive.
drives, but should use the
DISMOUNT command to OPR.
__________________________________________________________________

8-12
TAPE STORAGE
TAPE STORAGE

8.3.2 How to Enable/Disable Tape Drive Allocation
8.3.2 How to Enable/Disable Tape Drive Allocation

To use tape drive allocation enter the command

______ __________ __________
ENABLE TAPE-DRIVE ALLOCATION

in the n-CONFIG.CMD file.

You can disable tape drive allocation on a tape drive by using the SET
TAPE-DRIVE MTAn: UNAVAILABLE command.

8.3.3 Tape Mounting Policy
8.3.3 Tape Mounting Policy

Occasionally, you may mount a tape that the system cannot read. For
example, the operator mounts a tape that has a density of 800 bits per
inch (bits/in) on a drive that does not support this density. The
system checks tapes for labels; even if this tape contains labels, the
incorrect density prevents the system from recognizing them.

With such errors, the system can be set up to immediately unload the
tape and protect it from being accidentally erased, or it can treat
the tape as unlabeled and continue processing.

If you do not want the system to classify these tapes as unlabeled,
you can place the TAPE-RECOGNITION-ERRORS command in the n-CONFIG.CMD
file with the appropriate argument. The format of this command
follows:

REGARD-AS-UNLABELED
TAPE-RECOGNITION-ERRORS
UNLOAD

The system uses REGARD-AS-UNLABELED if no entry is made in the
n-CONFIG.CMD file. If REGARD-AS-UNLABELED is in effect, you should
instruct operators to be especially careful when mounting tapes with
write rings. The tape's contents cannot be overwritten if the write
ring is not inserted.

8.4 TAPE LABELING
8.4 TAPE LABELING

This section describes what tape labels are and how, as system
manager, you can initiate using them.

Magnetic tape labels are records that are interspersed with
user-defined data on a tape. They are informational records that
describe the user data in a standard fashion that is recognized by
many computer systems.

8-13
TAPE STORAGE
TAPE STORAGE

The TOPS-20 tape labeling system allows you to read and write tape
labels that conform to ANSI (American National Standards Institute)
and DEC standards. The tape labeling system also allows you to read
tapes that are labeled according to IBM labeling standards.

Tape labeling is an option. You can start or continue to run your
system using unlabeled tapes. If you have hundreds of unlabeled tapes
at your installation, you may decide not to convert entirely to a
labeled shop. Instead, you may have a combination of labeled and
unlabeled tapes.

Sections 8.4.1 through 8.4.3 describe the advantages of using tape
labels and how to set up your system to begin labeling tapes. The
_______ ____ __________ ______
TOPS-20 Tape Processing Manual provides a complete description of the
ANSI, DEC, and IBM standard label formats and how to use them. It
also describes the interface between the operator and magnetic tapes
and the user and magnetic tapes.

8.4.1 Why Tape Labels?
8.4.1 Why Tape Labels?

An unlabeled tape has a gummed label on the outside of the reel that
identifies the contents of the tape. When the operator selects,
mounts, and types the identity of an unlabeled tape, the system
assumes that the mounted tape is the one that the user (or job)
requested. No checking is performed by the system.

A labeled tape, however, contains standardized information on the tape
itself that identifies and describes the data on the tape. This
internal label information is in addition to the gummed label on the
outside of the reel. With labeled tapes, the operator selects a tape
(by looking at the outside gummed label), mounts the tape on any
available drive, but does not type in any identifying information at
the terminal. When a user issues a MOUNT request for a labeled tape
that is already mounted, the system automatically locates the drive
containing the tape requested, and checks to ensure that the correct
tape has been mounted. This facility for automatically locating and
checking tapes is described further below.

A labeled tape consists of a volume label group, followed by one or
more files. (A volume is a reel of magnetic tape.) The volume label
group is a set of one or more records at the beginning of the tape.
It contains a volume identifier, commonly referred to as a VOLID, and
other identifying information. (See Figure 8-1.) You, as system
manager, select the VOLIDs to be used at your installation. The VOLID
is a name containing from one to six alphanumeric characters. A user
requests access to a specific volume by specifying its VOLID to the
system.

8-14
TAPE STORAGE
TAPE STORAGE

Each file on a labeled tape contains a file header label group, the
file data (written by the user program), and a file trailer label
group. (See Figure 8-1). Optionally, the file can contain user
labels, whose contents are specified and examined only by user
programs. Volume labels, header labels, trailer labels, and user
_______ ____ __________ ______
labels are described in the TOPS-20 Tape Processing Manual.

_____________________________________________________________________________
| | V L | H | | T | | H | | T |
| | O A | E | | R | | E | | R |
| | L B | A | | A | | A | | A |
| | U E | D | FILE DATA | I | | D | FILE DATA | I |
| | M L | E | | L | | E | | L |
| | E | R | | E | | R | | E |
| | | | | R | | | | R |
|_|_______|_____|_______________|_____|_|_____|_______________|_____|_____

Figure 8-1: Organization of Labeled Tapes
Figure 8-1: Organization of Labeled Tapes

Because every labeled tape contains a unique identifier, or VOLID, the
system can read this VOLID and ensure that the correct tape has been
mounted. This automatic checking improves the reliability of your
tape system. It significantly reduces the likelihood of an operator
mounting the wrong tape.
Also, some or all of your tape drives can be set to automatically
recognize tape volumes as they are mounted. This process is called
automatic volume recognition (AVR). Setting AVR means that after the
operator mounts a tape, the system automatically reads the first
record and inspects it for label information. If the tape contains no
labels, the system classifies it as unlabeled and the operator must
key in a volume identifier for the tape. If a request for the tape is
pending, the system readies the tape for use by the requesting job.
If a request for the tape is not pending, the system stores the VOLID
in a table and waits for a request. Therefore, automatic volume
recognition provides the following benefits.

o The operator does not have to type tape-identifying
information to the system when mounting a labeled tape.

o It provides a faster connection between a user's job and the
tape requested.

o The operator can mount a tape long before it is needed. When
a job requests the tape, the system locates the drive that
contains the requested tape and readies it for use.

8-15
TAPE STORAGE
TAPE STORAGE

Tape labels also improve the security of your tape system.
DEC-standard labels identify the owner, as well as the volume, in the
volume label. The file labels specify protection codes for the
individual files. These labels protect a tape from being
inadvertently written on and valuable data destroyed by a user who
does not have the appropriate access rights to the tape or its files.

In addition to the added reliability, security, and volume
recognition, labeled tapes provide you with a means of interchanging
tapes between DECSYSTEM-20s and other computers. This interchange
capability extends the mobility of data between different systems.
You can write ANSI- and DEC-standard labeled tapes and mount these
tapes on other systems using ANSI- or DEC-standard labels, and vice
versa. You can mount a labeled tape that was written in EBCDIC with
labels conforming to IBM's OS standards, and read it on a DECSYSTEM-20
as if it were ANSI-standard labeled.

Finally, if you are using the TOPS-20 tape drive allocation facility,
you can charge users for their tape usage. Note that you must use
tape drive allocation with labeled tapes, but you can use it with
unlabeled tapes also. The accounting usage file contains entries for
_______ _____ ____ _____________
all tape-mount requests. The TOPS-20 USAGE File Specification
describes the formats of these entries and how they are used in
reports and billing.

8.4.2 Setting Up the System to Use Tape Labels
8.4.2 Setting Up the System to Use Tape Labels

To use tape labels, you must have at least one tape drive that is
9-track and has the capability of using tapes at a density of 800,
1600, or 6250 bits per inch (bits/in). There is no restriction on the
number of these drives you use. The TOPS-20 Tape Labeling system can
be used with as many drives as are allowed for your system.

Also, you must enter the ENABLE TAPE-DRIVE-ALLOCATION command in the
_______ __ _____ _ ____________ _____
n-CONFIG.CMD file. The TOPS-20 KL Model B Installation Guide
describes the format of this command and how to enter it into the
n-CONFIG.CMD file at the time you install the system. If you do not
enter this command during software installation, you can edit the
n-CONFIG.CMD file at a later date. However, if you edit the file at a
later date, you must shut the system down and bring it back up again
to process the commands in the n-CONFIG.CMD file.

8-16
TAPE STORAGE
TAPE STORAGE

8.4.3 Initializing Tapes and Drives to Use Labels
8.4.3 Initializing Tapes and Drives to Use Labels

Tapes must be initialized before they can contain labels. An
initialized tape contains a volume label set followed by an empty
file. The operator issues commands to OPR to initialize tapes for use
by the TOPS-20 Tape Labeling system. All the necessary volume labels
_______ __________ _____
are then created on a tape. (Refer to the TOPS-20 Operator's Guide
for a description of using OPR to initialize tapes.)

You should initialize as many scratch tapes as you will need to store
your system's data before users start issuing MOUNT requests for
tapes. Then, when a user issues a MOUNT command without specifying a
VOLID, the operator mounts an initialized scratch tape of the
appropriate label type. TOPS-20 then readies (loads) the tape for
write access by the user program.

In addition to initializing tapes, you can set some or all of your
tape drives to use the automatic volume recognition facility (AVR).
As described earlier, AVR sets your tape drives to automatically
recognize tape volumes as they are mounted. To turn on automatic
volume recognition, have the operator enter the following command in
the SYSTEM.CMD file:

ENABLE AUTOMATIC-VOLUME-RECOGNITION (FOR) object

Where object is either TAPE-DRIVE MTAn: or TAPE-DRIVES.

You can turn off AVR by entering the following command in the
SYSTEM.CMD file:

DISABLE AUTOMATIC-VOLUME-RECOGNITION (FOR) object

These commands can be given to OPR at any time to enable or disable
AVR for any or all drives on the system.

It is generally a good practice to enable AVR for all drives.

8-17
TAPE STORAGE
TAPE STORAGE

8.5 SHARING TAPE DRIVES BETWEEN TWO SYSTEMS
8.5 SHARING TAPE DRIVES BETWEEN TWO SYSTEMS

If you have two DECSYSTEM-20s, you can set up the systems to share a
TX02 tape subsystem by use of the TX03 option, as Figure 8-2 shows:

______________ ______________
| | | |
| DECSYSTEM-20 | | DECSYSTEM-20 |
|______________| |______________|
| |
___|___ ___|___
| DX20 |____ ____| DX20 |
|_______| | | |_______|
| |
| |
| |
| |
| |
Standard Single ___|______________|___ TX03 Dual-Channel
Channel----->| | | |<-----Option
|________| |_______|
| |
| TX02 |
| |
|______________________|
/ | | | \
/ | | | \
__/_ __|_ __|_ __|_ _\__
| | | | | | | | | |
| | | | | | | | | |
| | | | | | | | | |<--------Tape Drives
| | | | | | | | | |
|____| |____| |____| |____| |____|

Figure 8-2: TX02 Tape Subsystem
Figure 8-2: TX02 Tape Subsystem

Note, however, that use of the drives must be under strict operator
control. Without this control, it is likely that two users, on
different systems, will eventually end up using the same tape.

8-18
TAPE STORAGE
TAPE STORAGE

Operator control is required because:

o Unlike disk drives, there is no mechanism to control the
porting of a tape drive between systems. If the tape drive
is available to the TX02, then it is available to any system
to which the TX02 is connected.

o Furthermore, the MOUNTR programs on the two systems do not
communicate, so they cannot coordinate access to the drives.
Thus, the MOUNTRs on the two systems would allow two users
access to the same physical tape drive.

________ __________
Operator Procedures

1. All drives that are not to be used by a particular system
should be set unavailable to MOUNTR with the OPR command:

OPR> SET TAPE-DRIVE MTAx: UNAVAILABLE

This command takes away control of the tape drive from MOUNTR
and writes an entry in the DEVICE-STATUS.BIN file. During
system reloads, MOUNTR reads this file, and if a tape drive
has been set unavailable, will never try to access or assign
the drive. Note that if DEVICE-STATUS.BIN is ever damaged,
then a new file is created at system startup. However, all
data and settings will have been lost, including data for the
drives that have been set unavailable. Therefore, the
operator will need to repeat this step.

2. Setting the drive unavailable to MOUNTR does not prevent a
user from reserving the drive with the ASSIGN command. To
prevent a user from assigning a tape that is set unavailable
to MOUNTR, a program under control of the operator should
assign to itself all of the "unavailable" drives. This
program should be run at system startup, before any users are
allowed to log in.

You could also control the assignment of tape drives with an
access control program. Refer to Section 11.1, Access
Control Program.

8-19
TAPE STORAGE
TAPE STORAGE

An example of re-porting a tape drive from system A to system B
follows. The operator:

1. Removes the tape (if any) from the tape drive that is to be
ported over to system B.

2. Sets the drive unavailable to MOUNTR on system A.

( OPR> SET TAPE-DRIVE MTAx: UNAVAILABLE )

3. Assigns the drive to a process under control of the operator
on system A.

4. Deassigns the drive from the process that is under operator
control on system B.

5. Sets the drive available to MOUNTR on system B.

( OPR> SET TAPE-DRIVE MTAx: AVAILABLE )

| In a CFS-20 cluster, a tape drive can be used from only one system at
| a time. A user may receive the error message: "Device in use by
| another system."

8-20

CHAPTER 9
CHAPTER 9

SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

This chapter describes the actions to take when you are faced with
various system problems. You may have to correct a problem with the
file system, act immediately after a power failure, or remove the CI
from system use. There may be times when you cannot trace a problem.
At such times, Digital Field Service can remotely run diagnostic
programs on your system. The following sections address these topics.

Errors that require you to correct a problem in the file system seldom
occur. However, if a problem of this nature arises, you can perform
four classes of file system corrections. From the least to most
severe, they are:

o Restore a single file in a directory

o Restore a single directory (other than )

o Restore

o Restore the entire file system

_______ __________ _____
The TOPS-20 Operator's Guide provides all the necessary information
for the operator to correct these types of problems. Sections 9.1
through 9.4 provide you with an overview of how these problems are
solved.

9-1
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

9.1 RESTORING A SINGLE FILE
9.1 RESTORING A SINGLE FILE

If you receive a request to restore a file for a user, you can use the
following procedure.

1. Look in the binder that contains the listing of the DUMPER
log files. (Chapter 7 describes creating DUMPER log files.)

2. Write down the file specification (including the structure
and directory) to be restored, and the date and number of the
tape containing the file. Be sure to indicate the
destination structure and directory if one or both are
different from the structure and directory from which the
file was saved.

3. Submit a request to the operator to restore the file.

9.2 RESTORING A SINGLE DIRECTORY
9.2 RESTORING A SINGLE DIRECTORY

If you receive a request to restore a directory, you can use the
following procedure.

1. Determine the structure that contains the directory.

2. Make sure you have a copy of the files in this directory on a
DUMPER tape. (Check the log files.)

3. Give the ^ECREATE command with the LIST subcommand. Write
down the list of parameters, for example, the directory
number, allocation, etc. You may need this information when
you re-create the directory.

4. Give the ^ECREATE command with the KILL subcommand for the
_______ __________ _____
directory. (The TOPS-20 Operator's Guide provides additional
procedures for deleting a single directory if the ^ECREATE
command with the KILL subcommand is unsuccessful.)

5. Using your DUMPER backup tapes, first restore the files from
the last FULL-INCREMENTAL DUMPER operation. Then, restore
files from each INCREMENTAL tape until the time when the
files were lost. Be sure the operator gives the CREATE
command to DUMPER to restore the directory parameters.

If the directory contains unreproducible information and it is not
backed up on tape, call Digital Software Services for assistance. It
___
may be possible to reconstruct the directory without losing the valid
information in it.

9-2
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

9.3 RESTORING
9.3 RESTORING

Each structure has its own and a backup
that is used by the system if the primary
is bad. The directory contains a
pointer to each first-level directory on a structure, as well as
several important system files. (Chapter 5 illustrates how
points to directories.) If is lost
on the system structure, users cannot access any files in the system.
If is lost on a mountable structure, users cannot
access files on that structure.

You can tell that the on the system structure is bad
if the operator's console prints any one of the BUGHLTs listed in
Table 9-1. When a BUGHLT appears on the console, the system stops. A
BUGHLT appears in the form:

**********
*BUGHLT name AT dd-mm-yy hh:mm:ss
*JOB:n, USER: user-name
*ADDITIONAL DATA: data,data,data
**********

The lines beginning with JOB: or ADDITIONAL DATA: may not appear.

Table 9-1: BUGHLTS
Table 9-1: BUGHLTS

__________________________________________________________________

BUGHLT Meaning
BUGHLT Meaning
__________________________________________________________________

BADROT is invalid

FILIRD The system could not initialize

FILMAP The system could not map into
memory

BADXT1 The index table is missing and cannot be created
__________________________________________________________________

9-3
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

may also be bad if you get the BOOT error ?FIL NOT
FND. If this error appears, be sure you have mounted all devices
correctly.

To recover from a bad , first determine which
structure contains the bad directory. If the bad is
on a mountable structure, you can run CHECKD with RECONSTRUCT
_______
ROOT-DIRECTORY and specify the proper structure. The TOPS-20
__________ _____
Operator's Guide details the procedure for determining the structure
and using CHECKD for reconstructing on mountable
structures.

If the bad is on the system structure, you can
instruct the system to use the backup system structure
and rebuild this directory. Section 9.3.1 describes
this procedure.

NOTE

If your first attempt to rebuild
fails, call your DIGITAL Field Service Representative.
_____
NEVER try to rebuild this directory twice on any
structure.

9-4
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

9.3.1 Rebuilding the System Structure
9.3.1 Rebuilding the System Structure

To rebuild on the system structure, halt the central
_______
processor and perform Steps 7 through 21 in Chapter 2 of the TOPS-20
____ _____ _ ____________ ______
KL10 Model B Installation Guide. The steps are shown below for
reference.

1. Type CTRL/backslash on the operator's console; the system
prints PAR>.

2. Type SHUTDOWN and press the RETURN key; the system prints a
few message lines.

_____________
PAR>SHUTDOWN
**HALTED**

%DECSYSTEM-20 NOT RUNNING

3. Mount System Floppy A in drive 0 (Step 7).

4. Mount System Floppy B in drive 1 (Step 8).

5. Mount the TOPS-20 Installation Tape on MTA0: (Step 9).

If the TOPS-20 Installation Tape is not your most recent
system backup tape, mount your SYSTEM BACKUP TAPE that
contains the monitor, TOPS-20 Command Processor, DLUSER,
DLUSER data, DUMPER, and save sets containing and
. (Refer to Section 3.2 for a description of special
system directories.)

6. Place the front-end HALT switch in the ENABLE position (Step
10).

7. Set the front-end switch register to 000007 (octal) (Step
11).

9-5
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

8. Press the ENABLE and SWITCH REGISTER switches simultaneously
(Step 12).

RSX-20F VB16-00 8:55 1-JAN-88

[SY0: REDIRECTED TO DX0:]
[DX0: MOUNTED]
[DX1: MOUNTED]
KLI -- VERSION VB1600 RUNNING
KLI -- ENTER DIALOG [NO,YES,EXIT,BOOT]?
KLI>

NOTE

The version and edit numbers in this manual
may differ from the numbers printed on your
console. The numbers on your console must be
equal to or greater than the numbers in this
manual.

9. Type YES and press the RETURN key (Step 13).

________
KLI>YES
KLI -- KL10 S/N: 2136., MODEL B, 60 HERTZ
KLI -- KL10 HARDWARE ENVIRONMENT
MOS MASTER OSCILLATOR
EXTENDED ADDRESSING
INTERNAL CHANNELS
CACHE
KLI -- RELOAD MICROCODE [YES,VERIFY,FIX,NO]?
KLI>

10. Type YES KLX and press the RETURN key (Step 14).

___ ________
KLI>YES KLX
KLI -- MICROCODE VERSION 2.0 [407] LOADED

NOTE

If your system has cache memory, the
following question appears previous to the
question in Step 11. (Step 15.)

KLI -- RECONFIGURE CACHE (FILE,ALL,YES,NO)?

Type ALL and press the RETURN key (Step 16).

________
KLI>ALL
KLI -- ALL CACHES ENABLED
KLI -- CONFIGURE KL MEMORY [FILE, ALL, REVERSE, FORCE, YES,
NO]?
KLI>

9-6
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

11. Type ALL and press the RETURN key (Step 17).

KLI -- CONFIGURE KL MEMORY [FILE, ALL, REVERSE, FORCE, YES,
NO]?
________
KLI>ALL
LOGICAL MEMORY CONFIGURATION
.
.
.
KLI -- LOAD KL BOOTSTRAP [YES, NO, FILENAME]?
KLI>

12. Type MTBOOT and press the RETURN key (Steps 18 and 19).

___________
KLI>MTBOOT
KLI -- CONFIGURATION FILE ALTERED
KLI -- WRITE CONFIGURATION FILE [YES,NO]?
KLI>NO
BOOTSTRAP LOADED AND STARTED

BOOT V11.0(315)

MTBOOT>

13. Type /L and press the RETURN key (Step 20).

_______
MTBOOT> /L
[BOOT: STARTING CHN:n DX20x:0 MICROCODE Vn(n)][OK]
[BOOT: LOADING][OK]
MTBOOT>

NOTE

The message concerning the DX20 microcode is
printed only if you are installing the
TOPS-20 software on a DECSYSTEM-20 with a
DX20 tape or disk controller.

14. Type /G143 and press the RETURN key (Step 21).

__________
MTBOOT> /G143

[FOR ADDITIONAL INFORMATION TYPE "?" TO ANY OF THE
FOLLOWING QUESTIONS.]
DO YOU WANT TO REPLACE THE FILE SYSTEM ON THE SYSTEM
STRUCTURE?

NOTE

Read Step 15 carefully before answering this
question.

9-7
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

15. Type N and press the RETURN key. You DO NOT want to clear
all the information on the disk packs. If you want to retain
all the information in the file system, always type N.

DO YOU WANT TO REPLACE THE FILE SYSTEM ON
______
THE SYSTEM STRUCTURE? N

[PS MOUNTED]

RECONSTRUCT ROOT-DIRECTORY?

16. Type Y and press the RETURN key. This causes the backup copy
of to be used.

______
RECONSTRUCT ROOT-DIRECTORY? Y

[RECONSTRUCTION PHASE 1 COMPLETED]

%%NO SETSPD

System restarting, wait...
ENTER CURRENT DATE AND TIME:

The system restarts and runs CHECKD to reconstruct the bit
table. The bit table contains one bit for every page in the
file system. If the bit is on, the page is available; if the
bit is off, the page is in use.

17. Type the date and time and press the RETURN key. Type Y and
press the RETURN key to confirm the date and time.

________ _________
ENTER CURRENT DATE AND TIME: 1-JAN-81 0931

YOU HAVE ENTERED THURSDAY, 01-JANUARY-1981 9:31AM,
______
IS THIS CORRECT (Y,N) Y
WHY RELOAD?

18. Type OTHER and press the RETURN key.

__________
WHY RELOAD? OTHER
[REBUILDING BIT TABLE]

NOTE

You should type a response to WHY RELOAD?,
that reminds you of why you did this
procedure. This response is stored in the
ERROR.SYS file. Refer to the
_______ ____ _____ _ ____________ _____
TOPS-20 KL10 Model B Installation Guide for a
complete list of valid abbreviations.

9-8
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

19. The system prints some standard messages, the output from
CHECKD, RUNNING DDMP, and the output from SYSJOB and PTYCON.

[REBUILDING BIT TABLE]

[WORKING ON STRUCTURE - PS:]

output from CHECKD

RUNNING DDMP

output from SYSJOB and PTYCON

_______ __________ _____
Refer to the TOPS-20 Operator's Guide for samples of the
output from CHECKD, SYSJOB and PTYCON.

20. Log in as user OPERATOR.

TOPS-20 SYSTEM, TOPS-20 Monitor 7(21017)
_____ ________ ___ _____________
@LOGIN (USER) OPERATOR (PASSWORD) --- (ACCOUNT) OPERATOR
Job 1 On TTY1 3-MAY-88 10:33:32

9.4 RESTORING THE ENTIRE FILE SYSTEM
9.4 RESTORING THE ENTIRE FILE SYSTEM

If you are still receiving random errors and cannot use the system,
you may have to restore the entire file system on the system
structure. Before doing this, you should contact your software
specialist to ensure that resorting to this procedure is necessary.
The procedure requires shutting down the system and reinstalling the
file system.

9.4.1 Re-creating the File System on the System Structure
9.4.1 Re-creating the File System on the System Structure

The following steps outline the procedure for restoring the file
system on the system structure.

1. Type CTRL/backslash to start the front-end command parser.

CTRL/backslash

PAR>

2. Type SHUTDOWN to stop the central processor; the system
prints a few messages.

_____________
PAR>SHUTDOWN
**HALTED**
%DECSYSTEM-20 NOT RUNNING

9-9
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

_______ __ _____ _
3. Start at Step 9 in Chapter 2 of the TOPS-20 KL Model B
____________ _____
Installation Guide and follow all the steps through Step 60.

In Step 9, instead of mounting the TOPS-20 Installation Tape,
mount your system structure SYSTEM BACKUP TAPE that contains
the monitor, TOPS-20 Command Processor, DLUSER, DLUSER data,
DUMPER, and save sets containing and .

4. After performing Step 60, restore your entire file system
using DUMPER. First run DUMPER, then mount your first reel
of the most recent full DUMPER tape and follow the procedures
_______ __________ _____
in the TOPS-20 Operator's Guide.

5. Re-create the front-end file system by following the
_______ __ _____ _
directions in Chapter 4 of the TOPS-20 KL Model B
____________ _____
Installation Guide.

6. Finally, restart the system by following the directions in
_______ __ _____ _ ____________ _____
Chapter 5 of the TOPS-20 KL Model B Installation Guide.

NOTE

Restore the incremental saves to obtain the most
recently saved files. Before restoring each
incremental tape, type DUMPER>CREATE to restore all
the directories that were created since the last time
you ran the DLUSER program.

9.4.2 Re-creating Mountable Structures
9.4.2 Re-creating Mountable Structures

If, after your efforts to correct errors on a structure other than the
system structure (using the command RECONSTRUCT ROOT-DIRECTORY to
CHECKD), you still cannot use the structure, you can re-create that
structure and restore all the directories and files. You can restore
structures other than the system structure during timesharing.

To restore a mountable structure you must:

1. Give the SET STRUCTURE IGNORED command to the OPR program to
prevent other users from mounting the structure while you are
re-creating it.

2. Run CHECKD to create the structure.

3. Run DLUSER to restore directory parameters for the structure
if you previously used the program to save the parameters.

4. Run DUMPER using the backup tapes for this structure. Give
the CREATE and RESTORE commands to DUMPER to restore all the
directories and files.

9-10
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

_______ __________ _____
The TOPS-20 Operator's Guide details the procedures for running CHECKD
and DUMPER to re-create a structure.

9.5 POWER FAILURES
9.5 POWER FAILURES

Unfortunately, power failures and brown-outs sometimes occur at
installations. You should be aware of the immediate steps to perform
and transmit this information to your operations people. The kind of
attention you should direct to this type of problem depends on the
type of outage you have. These steps can protect your system from
physical damage and perhaps unnecessary loss of files.
If your system experiences a total power failure, you should:

1. Immediately power-off all components of the system.

2. Inform your DIGITAL Field Service representative as to when
you expect to resume power. The field service representative
may ask to be present while you bring your system back up.

If your system experiences a short instance of a power failure or
brown-out, the system may recover on its own. You may not have any
problems and, usually, all your data remains intact. If you notice a
problem, call your Field Service representative.

High-performance computer systems are sensitive to the quality of the
electrical power supply. An investment in a power conditioner or an
uninterruptible power supply may more than repay itself in improved
system reliability and availability. Your Field Service
representative may be able to assist you in evaluating the need for
such equipment.

9.6 REMOTE DIAGNOSTIC LINK (KLINIK)
9.6 REMOTE DIAGNOSTIC LINK (KLINIK)

You may occasionally have a problem with your system and cannot
determine the cause. The remote diagnostic link, available on all
systems, allows a DIGITAL Field Service engineer to access your system
from a remote location and run diagnostic programs. This capability
is called KLINIK. The DIGITAL engineer accesses KLINIK through a
terminal and telephone line at the DIGITAL Service Center. The
_______ __________ _____
TOPS-20 Operator's Guide describes when and how to use the KLINIK
capability.

9-11
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

9.7 MAKING THE CI UNAVAILABLE ON NON-CFS SYSTEMS
9.7 MAKING THE CI UNAVAILABLE ON NON-CFS SYSTEMS

The CI, a computer-interconnect bus, is a key piece of hardware for
connecting systems in a CFS-20 configuration and for connecting
HSC50-based disks (RA81s and RA60s) to a system. Ordinarily, you need
do nothing at all to operate the CI. However, you may need to
disengage a system from the CI so Field Service personnel can correct
problems with the CI20 or the HSC50. At those times, you should
instruct the operator to make the CI unavailable by means of the SET
PORT CI UNAVAILABLE command. (Refer to the TOPS-20 Operator's Guide
for details.)

When the CI is unavailable to a system, users cannot access
HSC50-based disks, which rely on the CI to transmit data. The
procedure calls for the operator to dismount any structures that the
system indicates are mounted on these disk drives.

To put the CI back in operation, the operator gives the command:

___ ____ __ ______________
OPR>SET PORT CI AVAILABLE

Structures that were affected must then be remounted.

Refer to Chapter 12, THE COMMON FILE SYSTEM, for information on
disengaging the CI on CFS systems.

9.8 MAKING THE NI UNAVAILABLE
9.8 MAKING THE NI UNAVAILABLE

A system may need to be disengaged from the NI so that field service
personnel can diagnose problems with the NI or the NIA20. To make the
NI unavailable to a system, the operator gives the command:

___ ____ __ ________________
OPR>SET PORT NI UNAVAILABLE

This command prevents users of the system from using LAT terminal
servers as well as any other software that uses the NI. If DECnet or
TCP/IP software is installed, it cannot use the NI for data transfer
between systems. To make the NI available again, the operator gives
the command:

___ ____ __ ______________
OPR>SET PORT NI AVAILABLE

9.9 OFFLINE DISKS
9.9 OFFLINE DISKS

When a disk unit becomes unavailable to a system, all jobs accessing
the disk "hang" until the disk becomes available again. When the disk
comes back online, input/output activity continues from the point
where it left off.

9-12
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

Also, some jobs may try to begin accessing the disk after it went
offline but before it becomes available again. They hang in the same
way that interrupted jobs, described above, hang. You can specify
that offline disks be made unavailable to these new jobs by putting
the following command in the n-CONFIG.CMD file:

ENABLE OFFLINE-STRUCTURES mm:ss

where:

mm:ss is the "structure timeout interval" in minutes:seconds
format. The structure timeout interval is the length of time
from when the system recognizes that a disk unit has gone offline
to when it marks the structure as offline. The maximum value for
mm:ss is 15 minutes; the minimum is 1 second.

It should be noted that if just one disk of a multidisk structure
becomes unavailable, then the entire structure is marked offline.
After a structure is marked offline, it becomes unavailable to new
jobs requesting input/output service. The system sends an error
message to any requestor trying to access the structure.

This command is in effect by default with a timeout interval of 5
seconds. To disable the feature, enter the following command in the
configuration file:

DISABLE OFFLINE-STRUCTURES

A good reason to disable the feature is to prevent batch jobs from
terminating when they receive the error message indicating that the
desired structure has been set offline. You may want batch jobs to
hang until the disk is restored for use.

9.9.1 Operator Procedures
9.9.1 Operator Procedures

Privileged commands corresponding to the ones above are available to
the operator during timesharing:

$^ESET OFFLINE-STRUCTURES mm:ss

$^ESET NO OFFLINE-STRUCUTRES

Operators may want to set the timeout interval to a value higher than
five seconds if they are able to correct the disk problem within the
specified period. However, new user requests will then hang until the
disk is marked offline (or the problem is corrected).

9-13
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

9.10 DUMPING ON NON-FATAL SYSTEM ERRORS
9.10 DUMPING ON NON-FATAL SYSTEM ERRORS

The monitor can dump its memory area to a disk file when BUGCHKs and
BUGINFs occur. This feature, called DUMP-ON-BUGCHK, helps you debug
the system of nonfatal, "continuable" errors by providing a dump file
for examination.

9.10.1 Enabling DUMP-ON-BUGCHK
9.10.1 Enabling DUMP-ON-BUGCHK

The DUMP-ON-BUGCHK feature is enabled in the n-CONFIG.CMD file with
the following command:

ENABLE DUMP-ON-BUGCHK FACILITY

At least one of the following commands is further required to enable
dumping of all or specific BUGCHKs or BUGINFs that can be dumped:

ENABLE DUMP-ON-BUGCHK ALL-BUGCHKS
ENABLE DUMP-ON-BUGCHK ALL-BUGINFS
ENABLE DUMP-ON-BUGCHK BUG bugname

where: bugname is the name of a BUGCHK or BUGINF

With the first two commands, each BUGCHK or BUGINF is dumped only once
per loading of the system. The third command causes a dump to be
taken each time that the specified BUGCHK or BUGINF occurs. Dumps are
taken only as often as the DUMP-ON-BUGCHK timeout allows, which is 15
seconds by default. The following command overrides the timeout
constraint and allows a dump to be taken as often as a specified bug
occurs:

ENABLE DUMP-ON-BUGCHK BUG bugname IGNORE-DUMP-TIMEOUT

9.10.2 Disabling DUMP-ON-BUGCHK
9.10.2 Disabling DUMP-ON-BUGCHK

You may want to disable this feature to save memory space that the
monitor uses to implement it, or after you've looked at the
considerations in Section 9.10.5. You could save the feature for
times when the system is experiencing problems.

If the feature is disabled, the system produces only the "crash" dumps
associated with fatal errors, but not "continuable" dumps. To disable
DUMP-ON-BUGCHK, enter the following command in the n-CONFIG.CMD file:

DISABLE DUMP-ON-BUGCHK

The DOB-ON-BUGCHK facility is disabled by default.

9-14
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

9.10.3 "Dumpable Structures"
9.10.3 "Dumpable Structures"

The operator can specify where continuable dumps are written with the
command:

___ _________ ____ _____________
OPR>SET STRUCTURE str: DUMPABLE

where:

str: is the name of a structure that is to be considered
"dumpable."

This command can be given for more than one structure. Note that the
system structure is always dumpable.

The dumpable status of a structure remains intact across crashes and
system reloads.

A continuable dump is written to the DUMP.EXE file on a
dumpable structure. The system writes the file to the first structure
that meets the following conditions:

o The structure is dumpable.

o The structure is not being initialized or dismounted.

o The structure is not offline, in maintenance mode, or write
locked.

o The data in the monitor's structure data block for the
structure appears to be uncorrupted.

o Any DUMP.EXE files on the structure have been copied
(see the following section) and therefore will not be
overwritten.

9.10.4 Copying the Dump File
9.10.4 Copying the Dump File

After the dump, the n-SETSPD program scans all dumpable structures and
copies any previously uncopied DUMP.EXE files to an area on
DMP:, if this logical name is defined. Otherwise, it copies the files
to other areas on the same structures. The new files have unique
names of the form:

9-15
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

str:DUMP-nnnn-bug.CPY.n

where:

str is the name of the structure

nnnn is the edit number of the monitor that was running at
the time of the crash

bug is the name of the BUGCHK or BUGINF

n is the file generation number

An informational message similar to the following is sent to the CTY
after each copy:

Copying system dump
from: ABC:DUMP.EXE.1
to: XYZ:DUMP-21002-FSPOUT.CPY.1

9.10.5 Time Considerations
9.10.5 Time Considerations

The DUMP-ON-BUGCHK facility (DOB) turns off timesharing while the
system is being dumped. If DOB takes an extended period of time, LAT,
| DECnet, or INTERNET connections may be lost. Therefore, you should
specify the fastest available device for DOB dumps. The following are
sample DOB times for various disk types and memory sizes:

______________________________________________________________________

Device Memory Size DOB Time
(megawords) (seconds)
______________________________________________________________________

RP07 1.5 06
RP07 4.0 16
RP06 1.5 11
RP06 4.0 32
RA60/81 1.5 21
RA60/81 4.0 56
______________________________________________________________________

9-16
SYSTEM PROBLEMS/CRASHES
SYSTEM PROBLEMS/CRASHES

Problems could occur in the following areas during extended dump
periods:

____ ____ ________ _____
o Data from Terminal Lines

During continuable dumps, the system is not in sufficient
communication with the front end to ensure that terminal
input data gets processed. (The monitor enters "secondary
_______ ______ _________ ______
protocol" -- refer to the RSX-20F System Reference Manual for
details). This data could get lost. It is a problem
particularly with lines doing high-speed input.

______
o DECnet

If other nodes in a DECnet network have their timeout periods
set at a value lower than the time it takes for a continuable
dump on this system, inter-system links could timeout.

___
o LAT

A LAT server has a default maximum timeout value of two
minutes, which should suffice for continuable dumps on the
host. However you can decrease the server timeout period.
If you make it too short, all jobs on the host could become
detached after the dump.

9.10.6 Controlling DUMP-ON-BUGCHK
9.10.6 Controlling DUMP-ON-BUGCHK

For your convenience, there is an unsupported program on the tools
tape that can help you control the DUMP-ON-BUGCHK facility. The tool
is called DOBOPR. It includes documentation that you can access with
the program's HELP command.

9-17

10-1

CHAPTER 10
CHAPTER 10

SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

The configurations of systems running TOPS-20 and the mix of jobs on
these systems vary from installation to installation. TOPS-20 is
designed to provide better response to interactive users than to
provide higher throughput to computational tasks. On systems with a
typical mix of interactive and batch jobs, this design provides both
good response and adequate throughput. Therefore, if your system has
many timesharing users and an average amount of batch processing jobs,
you will find that your system's response is good and most users are
satisfied.

If you have a mix of jobs or a configuration different from a typical
system, you may want to change the response of your system to provide
better service to specific users. TOPS-20 provides several tuning
mechanisms that allow you to experiment with and change the behavior
of your system. One mechanism allows you to favor classes of users by
allocating each class a specified percentage of the CPU. Another
mechanism allows you to favor computational jobs over interactive
jobs. A third mechanism allows you to disable features that normally
provide better performance, but that may not be applicable at your
installation.

This chapter describes the mechanisms for tuning your system's
response and provides guidelines for using these mechanisms. Because
the response of your system can be felt during actual use only, you
can expect system tuning to be an experimental and iterative process.
By analyzing the statistics from the WATCH program and by gathering
inputs from your users, you can determine the best way to tune your
system.

The tuning mechanisms include:

o The class scheduler, which allows you to divide the central
processor (CPU) resource among groups of users

o Assigning low priority to batch jobs for installations that
do not use the class scheduler

10-1
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

o Bias control, which allows you to favor either interactive or
compute-bound jobs on your system

o The program name cache for improving the startup time of
frequently used programs

o Reinitializing disk packs in heavily used structures for
improving file processing time

Each mechanism can be used independently. Unless otherwise noted,
there is no interrelationship among them.

10.1 THE CLASS SCHEDULER
10.1 THE CLASS SCHEDULER

Occasionally, certain jobs monopolize the central processor's time
while other more critical jobs wait for the CPU. You may want to
control the amount of CPU time a job receives. You can use the class
scheduler to provide an even distribution of CPU time or to provide
more CPU time to critical jobs on the system. Some system managers
may want to allocate a larger amount of processor time to special
users than to other system users. Sections 10.1.1 through 10.1.9
describe:

o an overview of the class scheduler

o who should use the class scheduler

o how to begin using the class scheduler

o turning on the class scheduler

o changing class percentages

o disabling the class scheduler

o getting information about class scheduler status

o a sample session using class scheduler commands

o an alternative to using the class scheduler with accounts.

10.1.1 Overview
10.1.1 Overview

The class scheduler allows you to allocate percentages of the central
processor's time to individual classes of users. Each job in a class
receives a portion of the class percentage. Therefore, by using the
class scheduler, you can provide a consistent service to predefined
groups of users.

10-2
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

The diagram below illustrates the concept of classes and percentages
of CPU time allocated to each class. Note that you can set up a class
to include all batch jobs. This allows you to control batch jobs
separately from timesharing jobs. The batch class is given a high
percentage or a low percentage. Now, each time a user submits a batch
job, the scheduler uses the batch class and not the user's class.
Section 10.1.4, Step 5, describes how to create a batch class.

__________________
| |
| |
| |
| RESEARCH |
| 40% | CLASS 2
| |
| |
|__________________|
| |
| |
| BATCH | CLASS 1
| 30% |
| |
|__________________|
| |
| ADMINISTRATION | CLASS 0
| 20% |
|__________________|
| STUDENTS |
|________10%_______| CLASS 3

You can define class memberships by using the TOPS-20 accounting
facility or by writing your own access control program. Section
10.1.9 provides an overview of using an access control program to
define classes. The following description applies to using the class
scheduler with the accounting facility.

Using the accounting facility, you can associate a class number with
each account on the system. Each account has only one class
associated with it. Therefore, only a user who has access to more
than one account can have access to more than one class. The user
changes classes by changing accounts. To use this method, you must
enable account validation so that users are required to use a valid
account. Section 10.1.4 describes the accounting file entries.

The scheduler periodically computes the time used by classes and
individual jobs within a class. The scheduler's first concern is that
a class receive its share of the CPU time. The scheduler gives a
greater percentage of time to the class that is the farthest away from
its target (the total percentage allocated to the class). The
scheduler's second concern is that each job within a class receive its
fair share. Periodically, the scheduler computes the average amount

10-3
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

of CPU time that a job has accrued. This quantity determines the
job's priority within the class. A job that is requesting the CPU and
is farthest way from receiving its fair share within the class
receives a greater percentage of time within that class.

Generally, the CPU has unused time. This unused time is called
windfall. Windfall occurs if one or more classes has no logged-in
jobs, or if one or more classes has an insufficient demand for the CPU
to use all of its class percentage.

You can handle windfall in one of two ways: allocate it or withhold
it. Allocating windfall means that the excess CPU time is awarded
proportionately to the active classes. (In this discussion, the term
active class refers to a class that has logged-in users requesting CPU
time.) Higher percentage classes receive proportionately more of the
available windfall than lower percentage classes. This means classes
can receive slightly more than their allowed percentages when there is
windfall available. Note that windfall is distributed proportionately
to each class and not to each job within a class.

Withholding windfall means that the excess CPU time is idle time and
it is not distributed to the active classes. It also means that
classes do not receive more than the percentage allowed for them.
Usually, it is better to allocate windfall, and not withhold it so you
don't throw away valuable computer time.

10.1.2 Who Should Use the Class Scheduler?
10.1.2 Who Should Use the Class Scheduler?

As mentioned earlier, the class scheduler allows you to divide the
user community into defined classes and allocate a percentage of CPU
time to each class. This intended use may not be beneficial or
practical for some systems. Tradeoffs do exist and some installations
do not require class scheduling. Therefore, read the following
paragraphs and determine if your system needs this type of control.
Several instances that can benefit from using the class scheduler are:

o You can elect to sell portions of CPU time. For example,
customer X can purchase some percentage of computer time at a
proportional cost. You should, in this case, invite customer
X to your installation and provide an environment that
simulates the kind of response this customer can expect at
this percentage. Because it is impossible to create the
environment exactly as the customer will experience it at all
times, customer X may decide later to change the purchase to
a different percentage.

10-4
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

o If you have a natural division among the users of the system,
you can divide these users into classes, then distribute CPU
time to these classes with respect to their importance on the
system. For example, in an educational environment, you may
have administrative users (doing payroll, grades, etc.),
faculty users (perhaps working on a funded research project),
and student users (who are computer science majors). Using
the class scheduler, you can establish three classes and
distribute the CPU time according to the importance or pay
rate of each class.

o If you wish to give preference to batch jobs, you can use the
class scheduler to give the batch class a high percentage of
the CPU.

Conversely, you may not want to use the class scheduler for some of
the following reasons:

o If you have not realized a need in the past for class
scheduling, or if you have a new system and do not see an
immediate requirement for class scheduling, you should not
set it up.

o Systems with minimal amounts of memory may experience an
increase in swapping. This additional overhead may offset
any advantage gained by using the class scheduler.

o In addition to other tasks, the scheduler constantly
maintains usage values for each class and job. Because of
this extra overhead, the overall system throughput decreases.
Therefore, use the class scheduler if allocating percentages
to individually defined classes outweighs the throughput
depreciation.

o To give batch jobs a low priority on the system, you do not
have to use the class scheduler. Section 10.2 describes
placing the BATCH-BACKGROUND command in the n-CONFIG.CMD file
to place all batch jobs in a low priority (or background)
queue.

10-5
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

10.1.3 How to Begin Using the Class Scheduler
10.1.3 How to Begin Using the Class Scheduler

If you elect to use the class scheduler, first divide the system users
into classes. Next, determine the amount of CPU time each class
should receive. Percentages given to classes are typically in units
of 5, that is, 5%, 10%, 15%, ....100%. The sum of the percentages
given to all classes cannot exceed 100 percent. The result of these
two steps depends on the reason you elected to use the class
scheduler, and how you plan to use it at your installation. Because
of this system dependency, step-by-step procedures for selecting
classes and allocating the CPU cannot be given. The following
discussion provides you with guidelines for setting up the class
scheduler to meet your system's needs.

o Start with as few classes as possible, three or perhaps four.
The class scheduler allows eight. Later, you can divide
classes further, if necessary.

o Determine the number of logged-in users you expect in each
class. Be sure that you do not overload a class, making it
impossible to give a sufficient percentage of the CPU to each
job in the class. Also, you can limit the number of users in
a class, but you cannot limit the number of jobs. For
example, the SUBMIT command creates an additional job.
Therefore, consider the type of work that users in a class
perform.

o Estimate the percentage of CPU time (or time purchased) each
class should receive. This is a difficult step; however, you
can experiment with and later alter the percentages you
choose. (Section 10.1.5 describes how you can change class
percentages.) If a class consists of a large number of users
who are generally logged in at the same time, be sure to give
this class sufficient CPU time. For example, using the
diagram below, class 2 has 60 members. It also has 60
percent of the CPU. This means that if approximately 60 jobs
in class 2 are demanding the CPU, each job will receive
approximately 1 percent. (It may be slightly greater than 1
percent if you allocate windfall.) This also means that on a
per-job basis, users in class 2, with the higher percentage,
may not get as much of the CPU as users in class 0 or class
1.

o In order to avoid possible performance problems, no class
should be allocated less than 5% of the CPU.

10-6
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

___________________
| |
| |
| |
| |
| |
| 60% | CLASS 2
| |
| |
| |
| |
| |
|___________________|
| |
| WINDFALL |
| |
|___________________|
| |
| 15% | CLASS 1
|___________________|
|_________5%________| CLASS 0

o The above diagram illustrates that you can allocate less than
100 percent of the CPU to classes. However, the total
percentage for all classes cannot exceed 100 percent.

o The system uses class 0 as a default for any account that
does not have a valid class assigned to it. Therefore, you
can divide a portion of the system into well-defined classes
and have all other users receive the percentage given to the
default class.

o You can set up the class scheduler so that one class, perhaps
the default class, receives only windfall. For example,
suppose you allow some users to log into an account that is
not yet assigned a class. These users are assigned to the
default class 0. Or, suppose several users log in
infrequently, read mail, and perform little computing. These
users may log into an account that is not assigned a class
(and, therefore, are assigned the default class, 0), or an
account that is associated with class 0. You subsequently
assign a zero percentage to class 0. These users may receive
enough windfall to get their job done. However, they are not
allocated CPU time and can have periods of extremely slow or
no response. You may find, after experimenting with this
type of procedure, that it is better to associate each
account with a class and give the class a very low percentage
of the CPU.

10-7
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

o Situations may arise that affect the scheduler's ability to
give a class its percentage of the CPU. For example, the
members of a class cannot use the amount of CPU time
allocated to the class. Also, a situation may arise where
the demands of the class exceed the percentage of CPU time
given the class, and windfall is available but not allocated.
In either case, you should reevaluate both the percentages
given to classes, and whether or not you want to continue
withholding or allocating windfall.

10.1.4 Procedures to Turn On the Class Scheduler
10.1.4 Procedures to Turn On the Class Scheduler

After dividing users into classes and estimating the amount of CPU
time, follow these steps to set up classes and turn on the class
scheduler.

____ _________
Step Procedure

1. Edit the ACCOUNTS.CMD file on the system structure
(and the subaccount files, if any, that contain all your
accounting data). Follow the procedure in Chapter 6,
Creating Accounts, for modifying or creating each account
with the /CLASS:n switch. For example,

_______ _____________
ACCOUNT COMP1/CLASS:1
_____ ___________________
USERS KOHN,HOLLAND,MILLER

means that when users Kohn, Holland, and Miller log into or
change their account to COMP1, they are placed in class 1.
Each account has only one class associated with it.
Therefore, only the user who has access to more than one
account can have access to more than one class. A job can
be in only one class at any one time.

2. Run the ACTGEN program. Give the TAKE command and specify
the ACCOUNTS.CMD file (or the file containing the
accounting data).

3. When ACTGEN returns its prompt, give the INSTALL command.
This command updates the ACCOUNTS-TABLE.BIN file that the
system uses to validate accounts.

4. Edit the n-CONFIG.CMD file to include the CREATE commands
that specify the classes. Be sure account validation is
enabled. That is, check that the DISABLE ACCOUNT VALIDATION
command is NOT in the file. (The system default is
ENABLED.) If account validation is disabled, users can use
any account and therefore any class they choose. Enter the
following commands in the order shown below.

10-8
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

The CREATE command defines the class number and the
percentage of CPU time the class should receive. For
example,

______ _ ___
CREATE 0 .40

means that the default class, 0, should receive 40 percent
of the CPU. Enter the CREATE command for each of the
classes that you defined in the ACCOUNTS.CMD file. For
example,

______ _ ___
CREATE 0 .40
______ _ ___
CREATE 1 .20
______ _ ___
CREATE 2 .30

NOTE

Remember that class 0 is the default class. Any
user whose account (this includes subaccounts) is
not associated with a specific class is placed in
class 0.

5. Next, if you have decided to place all batch jobs in a
separate class, enter the BATCH-CLASS command. For example,

___________ _
BATCH-CLASS 2

means that all batch jobs will be placed in class 2
regardless of the user's associated class. You must use the
CREATE command to define the percentage of CPU time that the
batch class should receive. Note that timesharing users can
be in the same class as well, if the account they use is
associated with that class. The CREATE command in step 4
defines class 2 to receive 30 percent of the processor. If
you do not place a BATCH-CLASS command in the n-CONFIG.CMD
file, the scheduler treats all batch jobs the same as
timesharing jobs.

6. Finally, enter the ENABLE CLASS-SCHEDULING command. Be sure
this is the last command entered. If you reverse the order,
that is, you enter ENABLE CLASS-SCHEDULING before the CREATE
commands and BATCH command, all users will receive zero
percent of the CPU.

The ENABLE CLASS-SCHEDULING command turns on the class
scheduler at the next system reload. It also specifies if
you are using accounting or an access control program
(policy program) for class scheduling and if you are
allocating or withholding the windfall. The format of this
command is:

10-9
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

ENABLE CLASS-SCHEDULING ACCOUNTS WITHHELD
POLICY-PROGRAM ALLOCATED

For example,

______ ________________ ________ _________
ENABLE CLASS-SCHEDULING ACCOUNTS ALLOCATED

means turn on the class scheduler, use the accounting
method, and allocate the windfall. Always allocate the
windfall. Do not withhold windfall unless you have a very
good reason to do so, and you are sure that your class
scheme works.

The entry,

______ ________________ ______________ _________
ENABLE CLASS-SCHEDULING POLICY-PROGRAM ALLOCATED

means turn on the class scheduler, use the policy (access
control) program, and allocate the windfall.

7. At the next system reload (the system is brought down and
back up again) the new commands in the n-CONFIG.CMD file
take effect.

10.1.5 Changing Class Percentages During Timesharing
10.1.5 Changing Class Percentages During Timesharing

During timesharing, you can change the percentage that a class
receives by using the SET command to OPR. This change lasts until
either the next system reload, or you make another change using the
SET command. The format of the SET command appears:

SET SCHEDULER CLASS (number) m (to percent) n

n can be from 0-99 inclusive. Note that the decimal point required in
the CREATE command is not allowed in this command.

To make the percentage that a class receives permanent, edit the
CREATE commands in the n-CONFIG.CMD file. For example, you can edit
the commands

______ _ ___
CREATE O .60
______ _ ___
CREATE 1 .30
______ _ ___
CREATE 2 .10

______ _ ___
CREATE 0 .10
______ _ ___
CREATE 1 .05
______ _ ___
CREATE 2 .80

10-10
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

Next, reload the system to process the commands in the n-CONFIG.CMD
file. The classes that received a low percentage before you made the
change now receive a higher percentage of CPU time.

Changing class percentage may be useful if you decide that users in
one or two classes should receive a greater percentage of CPU time
than other classes during the day. However, these high-percentage
classes may not require this time during the evening shift. If you
have a recurring need for such changes, you may want to put the
appropriate commands into files for use with the TAKE command in OPR.

10.1.6 Disabling the Class Scheduler During Timesharing
10.1.6 Disabling the Class Scheduler During Timesharing

You can turn the class scheduler off and back on during timesharing by
using the DISABLE and ENABLE commands to OPR. The class scheduler
remembers the class percentages that were in effect before the DISABLE
command was given. For example, suppose you use the SET command to
change the percentage that class 1 should receive from 05 to 15
percent. Then, you give the DISABLE CLASS-SCHEDULER command, and
later give the ENABLE CLASS-SCHEDULER command. The class scheduler
uses 15 percent for class 1. If you reload the system after disabling
the class scheduler, the class scheduler is enabled again and uses the
percentages given in the n-CONFIG.CMD file.

10.1.7 Getting Information About Class Scheduler Status
10.1.7 Getting Information About Class Scheduler Status

Several TOPS-20 commands provide information about different class
scheduler statistics.

The INFORMATION (ABOUT) SYSTEM-STATUS command informs you if:

o the class scheduler is enabled or disabled

o the accounting method or an access control program is being
used

o windfall is allocated or withheld

o the system's batch jobs are in a separate class.

For example

___________ __________________
@INFORMATION (ABOUT) SYSTEM-STATUS

CLASS SCHEDULING BY ACCOUNTS ENABLED, WINDFALL ALLOCATED, BATCH CLASS 1.

10-11
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

The INFORMATION (ABOUT) MONITOR-STATISTICS command provides a table
that shows each active class, its target use of the CPU, its current
use of the CPU, and the load averages for that class. For example,

___________ _______________________
@INFORMATION (ABOUT) MONITOR-STATISTICS

Class Share Use Loads

0 0.80 0.79 6.56 4.36 3.57
1 0.15 0.21 5.46 1.38 .95
2 0.05 0.00 0.00 0.00 0.00

The SYSTAT command outputs load averages for either the entire system
or a specific class. When the class scheduler is disabled, these
averages represent the load of the entire system. For example,

___________
@SYSTAT
Wed 11-Jul-88 10:17:09 Up 11:38:12
52+16 Jobs Load av 5.30 4.03 4.86

The last three numbers following Load av indicate the average number
of runnable processes over a period of one minute, five minutes, and
fifteen minutes. These numbers start at zero. The higher the numbers
the longer a job has to wait for CPU time on the average. Using the
example, over a fifteen minute period, a given job demanding the CPU
waits approximately 4.86 times longer to run than it would if it were
the only job running on the system.

When the class scheduler is enabled, these load averages represent the
status of the job doing the SYSTAT command and not the entire system.
For example,

___________
@SYSTAT
Wed 11-Jul-88 10:28:07 Up 11:49:12
52+10 Jobs Load av (class 1) 1.79 2.36 2.88

The last three numbers following Load av indicate the load averages of
the class that the job giving the SYSTAT command is in. The SYSTAT
command with the CLASS argument provides a breakdown of each job on
the system. This breakdown includes the class each job is in, the
average share of the class percentage that this job can receive, and
_______ ________
how much CPU time the job is currently using. The TOPS-20 Commands
_________ ______
Reference Manual describes these commands in detail.

10-12
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

10.1.8 A Sample Session
10.1.8 A Sample Session

The following examples show:

o The ACCOUNTS.CMD file after associating classes with
accounts.

o The procedures that you follow after editing all your
accounting files.

o A sample of the class scheduling commands that are placed in
the 7-CONFIG.CMD file.

!The ACCOUNTS.CMD file has been edited.

____ ________________________________
$TYPE (FILE) MAIN:ACCOUNTS.CMD

ACCOUNT MYBANK/CLASS:2
USERS BLOUNT,KONEN,ENGEL

ACCOUNT TRUST/CLASS:1
USERS BRAITHWAITE,HURLEY,HALL,CRISS

ACCOUNT OVERHEAD
USERS SAMBERG,BERKOWITZ,TAYLOR

ACCOUNT PROG/CLASS:3
USERS BLOUNT,KOHN,HOLLAND

!Notice that account OVERHEAD uses the default class, 0.

!Next, run the ACTGEN program.

___ ___________
$RUN ACTGEN
____ ________________________________
ACTGEN>TAKE (COMMANDS FROM) MAIN:ACCOUNTS.CMD

!After ACTGEN finishes and returns its prompt, give the
!INSTALL command to create a new version of the
!ACCOUNTS-TABLE.BIN file

____________
ACTGEN>INSTALL

!After ACTGEN finishes and returns its prompt, give the
!EXIT command

_________
ACTGEN>EXIT
$

10-13
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

____ ________________________
$TYPE SYSTEM:7-CONFIG.CMD

!Terminal Speeds
TERMINAL 1 SPEED 2400
TERMINAL 2 SPEED 9600
TERMINAL 3 SPEED 2400
TERMINAL 4 SPEED 2400
TERMINAL 5 SPEED 300
TERMINAL 6 SPEED 300
DEFINE SYS: MAIN:
DEFINE SYSTEM: MAIN:
DEFINE NEW: MAIN:,SYS:
DEFINE OLD: MAIN:,SYS:
DEFINE HLP: MAIN:,SYS:
MAGTAPE 0 40672 TU72
MAGTAPE 1 37719 TU72
PRINTER 0 VFU SYS:NORMAL.VFU
PRINTER 0 LOWERCASE RAM SYS:LP96.RAM
TIMEZONE 6

!Commands for the class scheduler

CREATE 0 .05
CREATE 1 .45
CREATE 2 .25
CREATE 3 .15
BATCH-CLASS 3
ENABLE CLASS-SCHEDULING ACCOUNTS ALLOCATED

To start the Class Scheduler, either reload the system, or give the
ENABLE CLASS-SCHEDULER command to OPR. If you edited the n-CONFIG.CMD
file to remove the DISABLE ACCOUNT VALIDATION command, you must reload
the system so you can start validating accounts.

10.1.9 An Alternative to Using Accounts
10.1.9 An Alternative to Using Accounts

Chapter 11 describes the access control program (policy program) that
is used to grant and restrict access to various system hardware and
software. This same program also includes the appropriate monitor
calls to handle class scheduler decisions. Among the requests it can
| define are classes at login.

NOTE

You CANNOT run the access control program to implement
class scheduler decisions at the same time you use the
accounting method. You must use one or the other.

10-14
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

10.2 SCHEDULING LOW PRIORITY TO BATCH JOBS
10.2 SCHEDULING LOW PRIORITY TO BATCH JOBS

The decision to favor batch jobs or to run them as background tasks
depends on the type of batch environment you have at your
installation. For example, if users submit batch jobs that are long
and/or that do not require completion immediately, you can give batch
jobs a low priority. Conversely, if batch jobs are the primary jobs
on the system, you can give them a high priority.

Section 10.1 describes how to place batch jobs in either a high or low
percentage class by including the BATCH n command in the n-CONFIG.CMD
file. When a user submits a batch job, the scheduler uses the batch
class and not the user's class.

You must use the class scheduler to give batch jobs a high priority.
If you are not using the class scheduler, you can give batch jobs a
| low priority. Do this in one of two ways:
|
| o Enter the BATCH-BACKGROUND command in the n-CONFIG.CMD file.
This command specifies that all batch jobs run on the lowest
priority queue, also known as the background queue. This
means that after processing all interactive jobs, the
scheduler selects and runs batch jobs waiting in the queue.
They receive left-over CPU time. You can enter the
BATCH-BACKGROUND command into the n-CONFIG.CMD file. The
command takes effect the next time you reload the system.

NOTE

The BATCH-BACKGROUND command is intended for
those who are not using the class scheduler
on their system but want to give the batch
jobs a low priority. You should not use this
command when you enable the class scheduler.

| o The operator can issue the SET SCHEDULER BATCH-CLASS n
| command at the OPR> prompt, where n can be BACKGROUND (batch
| jobs are run in the lowest priority queue or NONE (batch jobs
| receive no CPU time).

10.3 FAVORING INTERACTIVE VERSUS COMPUTE-BOUND PROGRAMS
10.3 FAVORING INTERACTIVE VERSUS COMPUTE-BOUND PROGRAMS

This section describes how you can influence the scheduler to favor
either interactive or compute-bound programs. You do this by using
the bias control, which is analogous to turning a knob over a range of
settings (from 1 to 20). When you select a lower number, the
scheduler favors users running interactive programs. When you select
a higher number, the scheduler favors users running computational
programs.

10-15
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

NOTE

You can use bias control with or without the class
scheduler enabled. However, the effect of the bias
control is less noticeable when used with the class
scheduler.

After you install TOPS-20 software, the system uses the default bias
control number 11. This setting distributes the scheduler's attention
evenly to interactive and compute-bound programs.

New users of TOPS-20 can use the default setting until they need to
favor particular types of programs. Previous users of TOPS-20 may
want to experiment with new control settings. For example, the bias
controls can serve as a good tool for favoring different types of
users at different times of the day. For instance, you can set the
bias to a low number during the day to favor on-line users and to a
high number during the evening to favor batch users. The response you
receive from your user community should determine the appropriateness
of the selected settings.

Setting the bias toward interactive programs gives better response to
the terminal user. Also, this setting may produce a higher system
overhead, because the scheduler swaps jobs and switches from different
tasks more often in its effort to favor interactive programs.
Generally, setting the bias toward interactive programs is beneficial
only if you have sufficient memory. Both the swapping rate and the
scheduler overhead are likely to increase in small systems with too
little memory. If your system has adequate memory, the scheduler
overhead should be fairly constant over most of the bias settings.

Setting the bias toward computational programs should reduce system
overhead and increase the total system throughput. However, the
response to the terminal user may decrease slightly. In some cases,
the improvement in system throughput more than compensates for the
lessened response time, and users are more satisfied.

As you experiment with the bias settings, remember that setting the
bias control to the extremes can prevent certain types of programs
from running for long time periods.

After you select a bias control number that fits your system's
operation, enter the BIAS CONTROL command in the n-CONFIG.CMD file or
use the SET SCHEDULER BIAS-CONTROL command to the OPR program.

10-16
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

The format of the command in the n-CONFIG.CMD file is:

BIAS CONTROL m

The format of the command to OPR is:

SET SCHEDULER BIAS-CONTROL (TO) m

where m is the bias control number. You can change the bias setting
during timesharing by using the SET SCHEDULER BIAS-CONTROL command.
However, when you reload the system, the bias setting in the
n-CONFIG.CMD file takes effect. If you want your change to be
permanent, edit the n-CONFIG.CMD file at a convenient time before you
reload the system.

Any time you are unsure of the current setting of the bias control,
give the INFORMATION (ABOUT) SYSTEM-STATUS command to determine its
setting.

10.4 IMPROVING PROGRAM STARTUP TIME
10.4 IMPROVING PROGRAM STARTUP TIME

Some of the programs on your system are run frequently. This involves
constant searching for the same file on disk, bringing the program
pages into memory, and allocating swapping space when the program is
swapped out of memory. By storing these programs in an easy-to-access
area, some of the startup time is saved. To improve the startup time
of the frequently used system programs, TOPS-20 keeps a program name
cache.

The PROGRAM-NAME-CACHE.TXT file is placed in the directory
on the system structure automatically at installation time,
and contains a list of programs and files to be copied into the
program name cache. These are:

SYS:PA1050.EXE
SYS:MACRO.EXE
SYS:EDIT.EXE
SYS:TV.EXE
SYS:LINK.EXE
SYSTEM:ERRMES.BIN

Each time you reload the system, the MAPPER.EXE program runs
under the SYSJOB program at the operator's console.
MAPPER.EXE reads the PROGRAM-NAME-CACHE.TXT file and
loads the program name cache. Now, when requests are made for these
programs, the system looks first in the program name cache to see if
it can retrieve the required pages quickly.

10-17
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

To further improve system performance, you can edit the
PROGRAM-NAME-CACHE.TXT file and add the filenames of your own
frequently accessed programs. For example, if your system uses the
FORTRAN language, you may want to add the files:

SYS:FORTRA.EXE
SYS:FOROTS.EXE
SYS:FORLIB.REL

Your list can contain the names of up to 16 executable files.
Therefore, select the files to be placed in the program name cache
carefully. You should consider only the executable files that are
started frequently by a large number of users. You can also add
library files to the program name cache, for example, SYS:FORLIB.REL.
However, these types of files use up swapping space. If you have too
many or very large files, you may create a detrimental effect on your
system's performance. The total library file pages that you cache
should be no greater than 200 to 300. Give the VDIRECTORY command for
the library files you want to cache and check the number of pages in
each file.

If you edit the cache file, the revised file takes effect (MAPPER
creates a new version of the cache) the next time you reload the
system. Alternatively, you can create a new version of the cache
immediately by entering the following commands at the operator's
console.

_______
^ESPEAK !talk to SYSJOB
____ ______
KILL MAPPER !kill old version of cache
___ ______________
RUN SYS:MAPPER.EXE !read new file and create
!new version of cache
__
^Z !exit

10.5 REINITIALIZING DISK PACKS
10.5 REINITIALIZING DISK PACKS

After many files are created, they may no longer be contiguous on the
structure (disk(s)). This scattering of files may increase the time
it takes to process them. You may decrease processing time by
reinitializing the disk packs in your heavily used structures. For
example, the system structure may be a likely candidate for
reinitialization. This procedure places files into a contiguous
format and can be scheduled as part of a backup procedure. How often
you reinitialize your packs depends on the work load of the system and
whether you notice a difference in system performance after following
this procedure.

10-18
SYSTEM PERFORMANCE
SYSTEM PERFORMANCE

Reinitializing disk packs requires that you dump all the directories
and files to tape, re-create the structure (and, in the case of the
system structure, reinstall the system), and restore all the
directories and files. Therefore, if you do not notice any
appreciable difference in your system performance after doing this,
don't schedule it on a regular basis, if at all.

_______ __________ _____
The TOPS-20 Operator's Guide describes re-creating the system
structure and other structures. Have the operator use this procedure
for reinitializing disk packs. If possible, have the operator
re-create the structure and restore the files to a different pack (or
set of packs) from the structure that you dumped. This ensures that
you do not lose your files should you have problems reading the tape
back to disk. That is, you still have the original structure intact
and can run DUMPER again to copy the files to another tape.

10.6 DYNAMIC DUAL PORTING
10.6 DYNAMIC DUAL PORTING

Dynamic dual porting refers to a disk drive that is dual-ported to one
system only. When one of the channels is busy transferring data for
another disk unit, input/output is automatically switched through the
other disk channel. Dynamic dual porting improves the performance of
input and output operations. It is activated automatically after
field service properly sets up the RP06 or RP07 disk drive(s), and the
operator places the drives' port switches in the A/B position.

Dynamic dual porting is not supported for RP20 disks. If it is tried,
only one path to the RP20 is used.

____________ _________ _______
The DECSYSTEM-20 Technical Summary describes the hardware associated
with input and output operations.

10-19

11-1

CHAPTER 11
CHAPTER 11

ACCESS CONTROLS
ACCESS CONTROLS

TOPS-20 provides control mechanisms that help you:

o Govern the access to many of your system's resources and
services

o Reduce or prevent unauthorized access to the system

o Provide an audit trail to help investigate occurrences of
unauthorized access

The following sections discuss these topics.

11.1 ACCESS CONTROL PROGRAM
11.1 ACCESS CONTROL PROGRAM

Previous chapters deal with administrative policies for allocating
resources. For example, Chapter 10 describes the policy decisions you
can make regarding the scheduler, and Chapter 8 describes the policy
decisions you can make regarding tape drive allocation and labeled
tape support.

In addition, you can make policy decisions that govern the access to
specific system resources. For instance, TOPS-20 allows a user to
change the speed of a terminal, assign a device, enable capabilities
at any time of day, mount a magnetic tape, and mount a disk structure.
However, you may want to restrict or disallow use of some of these
facilities. You may want only specified users at specified times of
the day and, perhaps, at specified terminals, to use certain
facilities. A particular mechanism lets you control the access to
such resources and services. With it, you have an additional means
for collecting accounting or other information.

11-1
ACCESS CONTROLS
ACCESS CONTROLS

| The following sections describe how to use this access control
| mechanism through the TOPS-20 access control program (ACJ). This
| program carries out your policy decisions in many areas. It can
control scheduling classes, the bias control, batch background queue,
logging in, use of physical resources (tape drives, terminals,
structures), and enabling capabilities. When a user requests a
resource (like ASSIGN TTY34:), your program identifies the user, the
| user's controlling terminal, and the type of request being made. The
program can merely log this information in a file, or make a decision
and tell the monitor to either grant or deny the request.
|
|
|
11.1.1 Starting the ACJ
| 11.1.1 Starting the ACJ
|
| You can start the ACJ in three ways:
|
_____ _________________________
| 1. $^ESET SYSTEM-ACCESS-CONTROL-JOB
|
| The advantage of starting the ACJ with ^ESET is that there is
| no corresponding ^ESET NO command to disable the ACJ.
| Starting the ACJ this way or by way of the configuration file
| is the most secure.
|
______ _________________________
| 2. ENABLE SYSTEM-ACCESS-CONTROL-JOB command in the configuration
| file
|
| 3. $ESPEAK command:
|
_______
| $^ESPEAK
| [Please type SYSJOB commands - end with ^Z]
___ ______________
| RUN SYSTEM:ACJ.EXE
__
| ^Z
|
| The disadvantage of using the ^ESPEAK command is that
| privileged users can disable the ACJ:
|
_______
| $^ESPEAK
| [Please type SYSJOB commands - end with ^Z]
____ ___
| KILL ACJ
__
| ^Z

11-2
ACCESS CONTROLS
ACCESS CONTROLS

11-3
ACCESS CONTROLS
ACCESS CONTROLS

11-4
ACCESS CONTROLS
ACCESS CONTROLS

11.1.3.1 ENABLE/DISABLE Command Functions
| 11.1.3.1 ENABLE/DISABLE Command Functions -
|
| NOTE
|
| You can specify ALL to enable or disable all
| functions.
|
|
| o ENABLE ACCESS
|
| This function controls the ACCESS, CONNECT, and END-ACCESS user
| commands. It is recommended that this function be enabled with
| the POLICY and LOG qualifiers so that an audit trail of failed
| accesses and user connections to their "owned" subdirectories is
| created. (Owned subdirectories are directories on any
| file structure that is DOMESTIC.) Directory owners are always
| allowed to connect to their "owned" subdirectories.
|
| o ENABLE ARPANET-ACCESS
|
| This function controls access to TCP/IP. The ACJ is activated
| each time a user tries to initiate an outgoing TCP/IP connection.
| The implemented policy allows access for users with SC%ANA
| capability only. To log all TCP/IP access and allow all users
| TCP/IP access, enable this function with NO POLICY.
|
| o ENABLE ASSIGN-DEVICE and ENABLE ASSIGN-DUE-TO-OPENF
|
| These identical functions help prevent two users on separate
| systems from accessing the same tape drive at the same time, if
| the two systems are not in the same CFS-20 cluster. This is
| important when there are shared tape drives between two or more
| systems.
|
| Only users with enabled WHEEL or OPERATOR privileges are allowed
| to assign magtape devices. The functions prevent non-enabled
| users from assigning magtape devices that are set UNAVAILABLE with
| the OPR command. All other devices are allowed.
|
| It is recommended that you enable this function with the POLICY
| and NOLOG qualifiers.

11-5
ACCESS CONTROLS
ACCESS CONTROLS

11-6
ACCESS CONTROLS
ACCESS CONTROLS

| o ENABLE CAPABILITIES
|
| This function controls the enabling of the capabilities described
| in Section 5.9.
|
| To allow all users to enable at any time and to log all capability
| changes, enable the CAPABILITIES function with the NO POLICY
| qualifier. Issue the DISABLE CAPABILITIES command to allow
| enabling at any time with no logging of activity.
|
| Setting WHEEL or OPERATOR capabilities is disallowed during
| non-prime time unless you have issued the USER
| ENABLE-NON-PRIME-TIME command (described in Section 11.1.4).
|
| If you use the USER ENABLE-NON-PRIME-TIME command (described in
| Section 11.1.4), it is recommended that you also use the LOG and
| POLICY qualifiers.
|
| The CAPABILITIES function provides an audit trail of all users who
| enable capabilities.
|
| o ENABLE CLASS-ASSIGNMENT
|
| The ACJ is activated for all attempts to set a job's scheduler
| class using the SKED% monitor call. An example of this is the OPR
| command SET JOB x SCHEDULER-CLASS y. However, if a user is not
| WHEEL or OPERATOR and is trying to set another job's class, the
| ACJ is not consulted and the user receives a CAPX1 error.
|
| o ENABLE CLASS-SET-AT-LOGIN
|
| The ACJ is activated each time a job logs in only if the class
| scheduler is on and class assignments are set by the policy
| program.
|
| The policy implemented is to use a SKED% monitor call to set the
| job in a particular class as specified by the user profile
| CLASS-AT-LOGIN (see Section 11.1.4). Because class zero is the
| default class, no SKED% monitor call is done if the CLASS-AT-LOGIN
| in the user profile is set to zero or if there is no user profile
| associated with the user logging in. If the job cannot be set in
| the proper class, the ACJ log file entry is marked as "unusual."

11-7
ACCESS CONTROLS
ACCESS CONTROLS

| o ENABLE CREATE-DIRECTORY
|
| This function prevents unauthorized manipulation of directories.
| It provides an audit trail of changes to directories and attempted
| break-ins since the last new username was created or a capability
| was changed.
|
| This function has the following effects:
|
| Users with OPERATOR capabilities are not allowed to make new
| usernames or changes to existing usernames on DOMESTIC
| structures. With TOPS-20, the boot structure and the public
| structure are always DOMESTIC and cannot be made FOREIGN.
|
| Setting passwords or user or directory groups on any
| is not allowed.
|
| Only enabled WHEELs can change the following directory
| attributes:
|
| SECURE
| FILES-ONLY
| WHEEL
| OPERATOR or SEMI-OPERATOR
|
| Nonprivileged users must create subdirectories with the
| FILES-ONLY and NO SECURE attributes.
|
| It is recommended that you enable the CREATE-DIRECTORY function
| with the LOG and POLICY qualifiers.
|
| o ENABLE CREATE-FORK
|
| This function controls the ability to create job forks. Each time
| a user runs a program, a process (fork) is created. The CFORK%
| monitor call is used to create forks. The ACJ is activated for
| each CFORK% monitor call that creates more than FKCNT forks.
| (FKCNT is a monitor cell that system programmers can patch; it is
| defaulted to 5.) The ACJ always allows the CFORK% monitor call.
|
| o ENABLE CREATE-JOB
|
| This function controls access to the CRJOB monitor call. The ACJ
| allows only enabled WHEELs or OPERATORs to perform the CRJOB%. To
| log all CRJOB-created jobs but let any user use CRJOB, enable this
| function with NO POLICY.

11-8
ACCESS CONTROLS
ACCESS CONTROLS

| o ENABLE CREATE-LOGICAL-NAME
|
| This function controls the ability to create systemwide logical
| names. The ACJ is activated for each of the following CRLNM%
| monitor call functions when the user is not a WHEEL or OPERATOR:
| CLNS1, .CLNSA, or .CLNSY. The LOG qualifier provides an audit
| trail of logical name activity.
|
| o ENABLE CTERM
|
| This function enables incoming CTERM connections by way of the SET
| HOST command. It also creates an audit trail, which provides the
______
| origin of the connecting user. (The @SYSTAT command displays user
| origins.)
|
| It is recommended that you enable this function with the LOG
| qualifier.
|
| o ENABLE DECNET-ACCESS
|
| This function allows access to the network for users with
| DECNET-ACCESS capability.
|
| It is recommended that you enable this function with the LOG
| qualifier to provide an audit trail of users who are accessing
| other systems through DECnet connections.
|
| o ENABLE DETACH
|
| This function controls the ability to detach jobs by way of the
| DETACH command. The ACJ always allows users to detach jobs. The
| LOG qualifier provides an audit trail.
|
| o ENABLE ENQ-QUOTA
|
| This function controls user setting of ENQ quota. The ACJ allows
| only a WHEEL or OPERATOR to perform the function.
|
| o ENABLE GET-DIRECTORY
|
| The GTDIR% monitor call provides information about a directory.
|
| The ACJ always allows the GTDIR% monitor call to succeed. This
| function is primarily to assure an audit trail whenever a user
| gets information about a directory (INFORMATION DIRECTORY
| command).

11-9
ACCESS CONTROLS
ACCESS CONTROLS

| o ENABLE GETAB
|
| This function controls use of the GETAB% monitor call (SYSTAT and
| INFORMATION MONITOR commands) to get information from the monitor.
| The ACJ is activated for each GETAB% when the previous context is
| not monitor. The ACJ always allows the GETAB%.
|
| You should enable this function with caution, because it increases
| system overhead and slows system response, especially when the
| activity is logged.
|
| o ENABLE HSYS
|
| This function allows only users with enabled WHEEL, OPERATOR, or
| MAINTENANCE privileges to shut down the system with the ^ECEASE
| command.
|
| o ENABLE INFO
|
| This function controls access to the INFO% monitor call to get
| information about systems in a CFS-20 cluster (SYSTAT NODE
| command) or to send clusterwide notices.
|
| You should enable this function with caution, because it increases
| system overhead and slows system response, especially when the
| activity is logged.
|
| o ENABLE LATOP
|
| This function allows enabled wheels and operators to implement
| .LARHC (request host connect) functions in the LATOP% monitor
| call. To log all LATOP% .LARHC functions and allow all users
| access to LATOP%'s .LARHC functions, enable this function with NO
| POLICY. These functions are performed regularly by LPTSPL for LAT
| printers.
|
| o ENABLE LOGIN
|
| The LOGIN function controls access to the system. A login request
| is denied if:
|
| The user tries to log in to .
|
| The user is over quota on the ps: directory.
|
| You specified with the USER command (described in Section
| 11.1.4) that the user cannot log in to this terminal line
| type.
|
| WHEEL-only logins are set and the user does not have WHEEL
| capability.

11-10
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| The login attempt is on a non-batch PTY.
|
| The user has OPERATOR capability and is trying to log in to a
| directory with WHEEL capability.
|
| It is important to enable the LOGIN function so that there is an
| audit trail for tracking "unusual" logins.
|
| It is recommended that you enable the LOGIN function with the LOG
| and POLICY qualifiers.
|
| o ENABLE LOGOUT
|
| The ACJ is consulted each time a user attempts to log out. The
| logout request is denied if the user is over quota on the
| ps: directory.
|
| The LOGOUT function helps capture a user session in an audit trail
| by showing when the user logged out.
|
| It is recommended that you enable the LOGOUT function with the LOG
| and POLICY qualifiers.
|
| o ENABLE MDDT
|
| This function allows access to internal monitor data structures.
|
| All non-WHEEL users are prevented from entering MDDT, because
| through MDDT, users can violate system security or crash the
| system. It is important to enable this function with the LOG and
| POLICY qualifiers so that an audit trail of MDDT entry is
| available in case of security problems.
|
| o ENABLE MTA-ACCESS
|
| This function controls access to magnetic tapes. The ACJ is
| activated for labeled MTA access in the following situations:
|
| o The label type is TOPS-20 and access is by non-owner and there
| is a protection failure.
|
| o ANSI labels are used and volume accessibility is not "full."
|
| o EBCDIC labels are used and the accessibility byte is from 1 to
| 3 inclusive.
|
| The ACJ always allows the access.

11-11
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| o ENABLE SECURE
|
| Four ENABLE/DISABLE command functions control access to "secure"
| files. These functions are described below. Refer to Section
| 11.7 for details on secure files.
|
| ENABLE SECURE CHFDB% allows a request to set or clear a file
| SECURE, based on settings in the ACCESS.CONTROL file. If there is
| no ACCESS.CONTROL file in the same directory as the file to be set
| secure, the request is allowed and logged as "unusual."
|
| ENABLE SECURE DELF% allows the request to delete a secure file
| based on settings in the ACCESS.CONTROL file. If there is no
| ACCESS.CONTROL file in the same directory as the file to be
| deleted, the request is allowed and logged as "unusual."
|
| SECURE OPENF% allows the request to open a secure file based on
| settings in the ACCESS.CONTROL file. If a read, write, or append
| access is attempted to a secure file and no ACCESS.CONTROL file is
| in the same directory as the secure file, the access is allowed
| and logged as "unusual."
|
| SECURE RNAMF% allows the request to rename a secure file based on
| settings in the ACCESS.CONTROL file. If rename access is
| attempted to a secure file and there is no ACCESS.CONTROL file in
| the same directory, the access is allowed and logged as "unusual."
|
| o ENABLE SET-TIME
|
| The STAD% monitor call sets the system time. The ACJ always
| allows the monitor call to succeed. This function is primarily to
| assure an audit trail whenever the system date and time are
| changed.
|
| o ENABLE SMON
|
| The SMON% monitor call sets or clears operating system features
| (such as account validation, logins allowed,...) and is usually
| invoked with commands in SYSTEM:7-CONFIG and the ^ESET command.
| The ACJ is activated for each SMON%.
|
| The ACJ allows only enabled WHEELs or OPERATORs to use the monitor
| call.
|
| It is recommended that you enable the function with the LOG and
| POLICY qualifiers, because SMON% changes TOPS-20 operating system
| parameters.

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| o ENABLE STRUCTURE-MOUNT
|
| This function controls mounting of disk structures. The ACJ is
| activated for every MSTR% monitor call "increment mount count"
| function (.MSIMC function). A job must have a "regulated" file
| structure mounted in order to use it.
|
| The ACJ always allows the increment of the mount count and lets
| normal file and directory protection handle security.
|
| o ENABLE SYSGT
|
| The SYSGT% monitor call extracts information from the monitor
| (SYSTAT and INFORMATION MONITOR commands). The ACJ is activated
| for each SYSGT% when the previous context is not monitor. The ACJ
| always allows the SYSGT%.
|
| You should enable this function with caution, because it increases
| system overhead and slows system response, especially when the
| activity is logged.
|
| o ENABLE TERMINAL-SPEED
|
| This function disallows the setting of terminal baud rate with the
| SET TERMINAL command unless the WHEEL or OPERATOR privilege is
| enabled.
|
| o ENABLE TLINK
|
| The ACJ is activated when the following commands are invoked from
| outside the monitor: ADVISE, TALK, BREAK, and REFUSE. The ACJ
| always allows these functions; however users can override them
| with the REFUSE commands.
|
| If the user is set SPY-ON (see Section 11.1.4), the log entry will
| be marked as "unusual."
|
| o ENABLE TTMSG
|
| The ACJ is activated when the ^ESEND and SEND commands are invoked
| from outside the monitor. The ACJ allows only enabled WHEELs or
| OPERATORs to use these commands and the associated monitor call
| (TTMSG%).
|
| o ENABLE USER-TEST
|
| This function is reserved for customer use. System programmers
| should refer to function code 400000 of the GETOK monitor call.

11-13
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11.1.3.2 ENABLE/DISABLE Function Qualifiers
| 11.1.3.2 ENABLE/DISABLE Function Qualifiers -
|
| The following are qualifiers that you can specify with the ENABLE and
| DISABLE commands described in Section 11.1.3.1.
|
| o [NO]POLICY
|
| Causes the enforcement of the ACJ policy on a particular
| ENABLE function. The default is POLICY. The NO POLICY
| qualifier is often combined with the LOG qualifier; without
| this qualifier, the effect is similar to the DISABLE
| function.
|
| o [NO]LOG
|
| Creates an entry in the ACJ log file that describes the
| function. The default is LOG.
|
| o [NO] CONSOLE
|
| The CONSOLE keyword enables display of the logging string to
| the console terminal. The default is NO CONSOLE.
|
| o [NO] DENY-BATCH
|
| The DENY-BATCH keyword causes a request for this function
| from any batch job to always be denied. The default is NO
| DENY-BATCH.
|
| o [NO] DENY-CTY
|
| The DENY-CTY keyword causes a request by a job logged into
| the system's console terminal (the CTY) to always be denied.
| The default is NO DENY-CTY.
|
| o [NO] DENY-DECNET
|
| The DENY-DECNET keyword causes a request by a job which is
| attached to the system through DECnet (NRT or CTERM protocol)
| to always be denied. The default is NO DENY-DECNET.
|
| o [NO] DENY-DETACHED
|
| The DENY-DETACHED keyword causes a request by a detached job
| to always be denied. The default is NO DENY-DETACHED.
|
| o [NO] DENY-LAT
|
| The DENY-LAT keyword causes a request by a job attached to
| the system through a LAT terminal to always be denied. The
| default is NO DENY-LAT.

11-14
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11-15
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| [NO] LOGIN-CTY
|
| Lets a job log in to the system through the system's console terminal
| (the CTY). The default is LOGIN-CTY.
|
| [NO] LOGIN-DECNET
|
| Lets a job log in to the system through DECnet using the NRT or CTERM
| protocol. Do not confuse this keyword with remote DECnet access using
| the RMSFAL (which is controlled by the LOGIN-DETACHED keyword). The
| default is LOGIN-DECNET.
|
| [NO] LOGIN-DETACHED
|
| Lets a job log in detached. Digital-supplied software that does
| detached logins is limited to DIU (Data Interchange Utility) and
| RMSFAL (RMS File Access Listener).
|
| [NO] LOGIN-LAT
|
| Lets a job log in to the system through a LAT terminal.
|
| [NO] LOGIN-LOCAL
|
| Lets a job log in to terminal lines connected to the DECSYSTEM-20
| (RSX20F console front end) that are not configured as REMOTE. LOCAL
| lines are normally connected directly to terminals rather than to
| communications equipment such as modems or port selecters.
|
| [NO] LOGIN-PTY
|
| Lets a job log in to a PTY that is not a batch job.
|
| [NO] LOGIN-REMOTE
|
| Lets a job log in to terminal lines connected to the DECSYSTEM-20
| (RSX20F console front end) that are configured as REMOTE. REMOTE
| lines are normally connected to modems or port-selecting equipment and
| not directly to terminals.
|
| [NO] LOGIN-TCP
|
| Lets a job log in to the system through a TCP/IP terminal (TELNET
| protocol).
|
| [NO] SPY-ON
|
| Users will be spied on when logging in or attaching to jobs. The
| default is NO SPY-ON.

11-16
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11-17
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| PRIME-TIME-END time
|
| Sets the time at which prime time ends on each weekday. This time is
| used when you issue the USER ENABLE-PRIME-TIME command with the ENABLE
| CAPABILITIES command. The default ending time is 18:00 (6 PM).
|
| SPY-CHECK-INTERVAL seconds
|
| Sets the time between TLINK% monitor calls to jobs that are being
| spied on. Shorter times increase overhead but lower the risk that
| spying data will be lost. The default is 10 seconds.
|
| SPY-LOG-DIRECTORY string
|
| Sets the initial part of the specification for spy log files. The
| string will have "-nodename.username" appended to it to complete the
| file specification. The default is SYSTEM:ACJ-SPY, so spy log files
| are of the form "SYSTEM:ACJ-SPY-nodename.username."
|
| The ACJ always makes spy log files secure.
|
|
|
11.1.6 SHOW Command
| 11.1.6 SHOW Command
|
| The SHOW command displays the items changed with the ENABLE, DISABLE,
| SET, and USER commands. The SHOW command is followed by one of the
| following keywords:
|
| o ALL
|
| Shows all information.
|
| o FUNCTION ALL keyword
|
| Shows the profile of all functions or of a particular
| function.
|
| o SETTINGS ALL keyword
|
| Shows all items or a particular item changed by the SET
| command.
|
| o USER ALL * or username
|
| Shows all user profiles or a particular user profile.

11-18
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11-19
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11-20
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11.1.10 Reviewing the Log Files
| 11.1.10 Reviewing the Log Files
|
| You should review daily the log files produced by the ACJ for possible
| unusual activity. Careful monitoring results in greater system
| security, because repeat penetrations cause the most severe security
| problems. The log file is always made "secure" (see Section 11.7) to
| prevent unauthorized access. A new generation of the log file is
| created each time the ACJ is run and each night at midnight.
|
|
|
11.1.10.1 Log File Format
| 11.1.10.1 Log File Format -
|
| The log file is split into pages with a header on each page. The
| first line of the header contains the ACJ version, system nodename,
| current date/time, and page number. The second and third lines
| summarize the activity so far: number of requests allowed, denied,
| and failed; CPU time used; and "uptime" of the ACJ.
|
| Each activity results in one line of text in the log file. The first
| item is the time of day. The second item is the username requesting
| the operator. (For the LOGIN function, the username that is trying to
| log in is in this field.) The next field is the access control
| function. Following the function, there is information about the job.
| This information consists of the job number, controlling job if the
| job is being run on a PTY, "batch" if it is a batch job, terminal
| number, network origin string if the job originates from a network
| terminal, and the job's current program name. Finally, the enabled
| capabilities of the process attempting access are displayed.
|
| Following that fixed information is a comma and information that is
| specific to this request type. For example, if a user is enabling
| capabilities, the desired capabilities are shown.
|
| At the end of the line one of three strings may appear.
|
| o [Denied] indicates that the ACJ denied the request. For
| example, a user tried to log in but is not allowed to log in
| to that terminal type.
|
| o [Failed] indicates that the ACJ allowed the request but that
| the action failed. For example, a user tried to log in but
| gave a bad password.
|
| o [Unusual] indicates that the ACJ allowed the request but it
| is in some way unusual. For example, a user logged in when
| that user is set SPY-ON. The conditions under which the
| request is considered unusual are documented in Section
| 11.1.3, ENABLE and DISABLE commands.

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11.1.10.2 Log File Examples
| 11.1.10.2 Log File Examples -
|
| This section shows sample entries from a typical ACJ log file.
|
| The following is a sample ACJ log file header. It shows that the log
| file was started at midnight and that the ACJ has been up about 12
| hours, processing 790 requests.
|
| ACJ 7(100) on GARK, Thursday, February 2, 1989 00:00:00, page 1
| Allowed 782 requests, denied 8 requests, 5 requests failed
| Used 1:09.32 in 11:57:56.69
|
| The following log file entries show a batch job execution. User
| OPERATOR running BATCON opened a PTY, assigned it to itself, and
| created a job, which logged in to user SCHMITT. That user enabled
| capabilities, and then the batch job ran to completion. The job
| running BATCON then logged out the batch job.
|
| 00:00:47 OPERATOR Open-assign job 194 ctrl 193 TTY233 GALAXY opr
| ana, device PTY7
| 00:00:47 OPERATOR Assign job 194 ctrl 193 TTY233 GALAXY opr ana,
| TTY241
| 00:00:48 OPERATOR CRJOB job 194 ctrl 193 TTY233 GALAXY opr ana
| 00:00:48 SCHMITT Login job 206 batch TTY241 EXEC, by OPERATOR job
| 194 ctrl 193 TTY233 GALAXY
| 00:00:49 SCHMITT Caps job 206 batch TTY241 ENABLE, desired whl
| 00:01:36 OPERATOR Logout job 194 ctrl 193 TTY233 GALAXY opr ana,
| target SCHMITT job 206 batch TTY241 EXEC
|
| The next two entries show an incoming CTERM connection from user
| SGAGNE on system GIDNEY, who proceeds to log in to this system.
|
| 08:35:49 OPERATOR Cterm job 0 Det SYSJOB, from GIDNEY::SGAGNE
| 08:35:55 SGAGNE Login job 214 TTY364 GIDNEY::SGAGNE(CTM) LOGIN
|
| Below, user GAS tried to attach to his detached job and apparently
| typed an incorrect password (see [Failed]). On the second try, he
| succeeded and attached to his job.
|
| 09:38:48 not-logged-in Attach job 214 TTY444 LAT1(LAT) ATTACH,
| target GAS job 207 Det DETACH [Failed]
| 09:38:58 not-logged-in Attach job 214 TTY444 LAT1(LAT) ATTACH,
| target GAS job 207 Det DETACH

11-22
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| Below, the first entry shows the OPERATOR job running MX connecting to
| system VAXVLN using DECnet. The second entry shows the MX job
| delivering mail to user APUCHRIK, who has a "secure" MAIL.TXT file.
| The third entry shows this same user accessing his mail file with MS.
|
| 09:39:32 OPERATOR DECnet job 198 ctrl 193 TTY237 MX opr ana, to
| VAXVLN
| 09:47:11 OPERATOR Secure-OPENF job 198 ctrl 193 TTY237 MX opr
| ana, read write PUBLIC:MAIL.TXT.1
| 09:49:15 APUCHRIK Secure-OPENF job 199 TTY435 LAT1(LAT) MS, read
| write preserve-dates PUBLIC:MAIL.TXT.1
|
| The first line below shows a user trying to set TTY3's terminal speed.
| The request is denied. The second and third lines show OPERATOR jobs
| running DUMPER to save the system. The second line shows that user
| RASPUZZI did not allow OPERATOR read access to a file; the access
| failed and the file is not backed up. The third line shows that a
| SECURE file was opened for reading, but there was no ACCESS.CONTROL
| file present in that directory. The request is marked as unusual, and
| access is allowed.
|
| 19:17:56 JWONG Terminal-speed job 216 TTY3 EXEC, TTY3 input 2400
| output 2400 [Denied]
| 19:38:00 OPERATOR Secure-OPENF job 215 ctrl 206 TTY243 DUMPER opr
| ana, read preserve-dates RANDOM:JAN89MAIL.TXT.1
| [Denied]
| 19:38:24 OPERATOR Secure-OPENF job 211 ctrl 206 TTY241 DUMPER opr
| ana, read preserve-dates WORK:BOBBIE.MAIL.1
| [Unusual]

11.2 PASSWORD ENCRYPTION
11.2 PASSWORD ENCRYPTION

One way to violate system security is through unauthorized use of
directory passwords. Having acquired someone's password, an intruder
could log in or gain access to restricted system resources. The
password encryption facility in TOPS-20, however, makes it harder to
steal passwords.

With encryption enabled, passwords entered into the system are
translated to an indecipherable cyphertext format before they are
stored or otherwise used. Nowhere in the system is the original
plaintext form of a password kept. As a further security measure, no
current TOPS-20 utility converts the cyphertext to plaintext.

NOTE

Password encryption is irreversible. Therefore,
before enabling encryption, be sure you will never
need to revert back to an earlier version of the
operating system.

11-23
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To enable password encryption, use the CHECKD program. You can do
_______ __
this during or after system installation. (Refer to the TOPS-20 KL
_____ _ ____________ _____
Model B Installation Guide for details.) With CHECKD, password
encryption is enabled on a structure-by-structure basis; after the
procedure, all passwords for a particular structure are encrypted as
previously described. If you enable encryption after installation,
run the KRYPTN program after CHECKD to convert existing plaintext
passwords on a structure to cyphertext. The KRYPTN program is located
on the tools tape, which is part of the TOPS-20 software installation
package.

Encryption should be enabled for all structures except those that will
be used on a TOPS-20 pre-Version 6 system. (Section 11.2.1 discusses
this topic.)

You can add your own encryption algorithm to the system if you choose
not to use TOPS-20's algorithm. Refer to Section 11.2.2.

Because the encryption algorithm is irreversible, care is required in
the following areas:

o Remembering one's password

o Working in a multiple-system environment

o Adding new algorithms to the system

o Using DUMPER

Mistakes in these areas could invalidate passwords so that they may
need to be respecified with BUILD or ^ECREATE. These interrelated
topics are discussed in the following sections.

11-24
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11.2.1 Moving Structures Among Systems
11.2.1 Moving Structures Among Systems

If you are in a multiple-system environment, you may need to move
structures from one system to another. Problems could arise, however,
if some systems are running TOPS-20 pre-Version 6 software and others
are running TOPS-20 Version 6. For example, when a structure
containing encrypted passwords is taken to a TOPS-20 pre-Version 6
system, any access to files on the pack that requires a password to be
supplied fails, because, in validating a password, the older monitor
simply compares the entered plaintext to the cyphertext stored on
disk. The older monitor is unfamiliar with the encryption process.

To avoid this problem, you should postpone encryption for relevant
structures until all systems are upgraded.

Any TOPS-20 system can correctly handle unencrypted structures.

You could also encounter problems in moving structures to other
systems if you use your own encryption algorithm. This topic is
discussed below.

11.2.2 Adding Encryption Algorithms to the System
11.2.2 Adding Encryption Algorithms to the System

You can use one or more of your own encryption algorithms exclusively
or in addition to TOPS-20's algorithm. For a description of the
procedures involved, refer to the monitor module, STG.MAC.

Each time a password is encrypted and stored in a directory, the
version number of the algorithm used to encrypt it is also stored.
This allows new encryption algorithms to be added to the system with
no impact on currently encrypted passwords, provided the old
algorithms have not been removed from the monitor. Only passwords
created since the installation of the new (current) algorithm will be
encrypted with that algorithm. Older passwords invoke the appropriate
algorithms during password-required accesses.

If you also want existing passwords to use the new algorithm, the
operator must individually respecify the passwords with BUILD or
^ECREATE. The operator does this after the new algorithm is
installed. Note that KRYPTN cannot be used here to convert existing
cyphertext to new cyphertext.

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In using your own encryption algorithms, be aware that directories on
structures and on DUMPER-created tapes include passwords that may be
unusable at other sites. Other TOPS-20 monitors could consider the
passwords' algorithm version numbers to be invalid. For example,
these monitors may acknowledge only the standard TOPS-20 algorithm.
Even if a site accepts the version numbers, its corresponding
algorithms may be different from the algorithms at your site. Thus,
on attempted password use, the cyphertext produced at this other site
could never match the stored cyphertext.

To address these problems, you could:

o Warn sites about the nature of the passwords on a tape or
structure. A site could then avoid using certain directories
or respecify a password with BUILD or ^ECREATE if necessary.

o Refrain from saving directory information on tapes bound for
other sites. That is, do not use DUMPER's CREATE command
when creating such tapes.

o Ship only directories that have null passwords. These
"passwords" are considered unencrypted, and should cause no
problem on any system.

11.2.3 Using DUMPER
11.2.3 Using DUMPER

Section 11.2.2 addressed using DUMPER with nonstandard algorithms.
This section continues the discussion of DUMPER.

Care must be taken when restoring directories that were saved with
DUMPER's CREATE command. Incompatible versions of tapes, DUMPER, and
TOPS-20, when combined, can produce a number of password-related
problems. Note the system's behavior during tape restoration for the
combinations in Table 11-1. In the table, tape Version 4 is the
version of tape that DUMPER Version 4.1 creates. Tape Version 5 is
the version of tape that DUMPER Version 5 creates.

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Table 11-1: DUMPER Directory Restorations
Table 11-1: DUMPER Directory Restorations

____________________________________________________________________

Tape Version DUMPER MONITOR Result
Tape Version DUMPER MONITOR Result
____________________________________________________________________

5 5 6 OK
4 5 6 OK (N1)

5 4.1 6 E1
4 4.1 6 OK (N1)

5 5 5 E2
4 5 5 OK

5 4.1 5 E3
4 4.1 5 OK
____________________________________________________________________

Legend:

N1 Passwords are correctly encrypted for the first time using
the monitor's current encryption algorithm.

E1 The tape version number is incompatible with this DUMPER.
DUMPER reports this fact before restoring the tape data. If
directories are restored from this tape, encrypted passwords
are re-encrypted, causing all uses of these passwords to
fail. The passwords will then have to be individually
respecified with BUILD or ^ECREATE. However, if a password is
unencrypted on the tape, then it is encrypted for the first
time, and will be usable.

Any files on this tape are restored correctly.

E2 Pre-version 6 monitors have no logic to handle
encryption-related data that the tape may contain. Therefore,
restored encrypted passwords are unusable and must be
respecified with BUILD or ^ECREATE. Note that directory
blocks on the tape may contain password descriptor
information, such as the encryption version number. This
descriptor data is not restored.

Any files on this tape are restored correctly.

E3 The tape version number is incompatible with this DUMPER.
DUMPER reports this fact before restoring the tape data. This
incompatibility results in the same situation as E2.

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If these problems occur often, users and operators could refrain from
saving directory information on tapes, or they could use null
passwords for directories that are to be saved. Null passwords are
considered to be unencrypted and should cause no access problems.

11.3 PASSWORD MANAGEMENT
11.3 PASSWORD MANAGEMENT

Encryption is just one part of password management. You should also
make sure that users at your site do not choose passwords that are too
short or that are otherwise easy to guess, such as one's name or
initials.
|
|
|
11.3.1 Setting Password Length
| 11.3.1 Setting Password Length
|
| You can set the minimum password length in the n-CONFIG.CMD file with
| the command:
|
______ _______________________ _
| ENABLE MINIMUM-PASSWORD-LENGTH n
|
| where:
|
| n is the minimum number of characters allowed for passwords,
| from 1 to 39 characters. A common value for n is 8
| characters.
|
| Or, you can issue the command:
|
_____ ____ _______________________ _
| $^ESET [NO] MINIMUM-PASSWORD-LENGTH n
|
| The @INFORMATION SYSTEM command reports the minimum password length
| set for your system.
|
|
|
11.3.2 Changing Passwords Regularly
| 11.3.2 Changing Passwords Regularly
|
| It would also be helpful for users to change their passwords
| regularly. You can enforce this through the ^ESET command and in the
| n-CONFIGURATION file:
|
_____ ____ ___________________ ____ _
| $^ESET [NO] PASSWORD-EXPIRATION (TO) N
|
| In the n-CONFIGURATION file:
|
______ ___________________ _
| ENABLE PASSWORD-EXPIRATION n
_______ ___________________
| DISABLE PASSWORD-EXPIRATION

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| Where:
|
| n is the date after which passwords expire
|
| n is the number of days a password is valid since the time it
| was last changed. This value for n is a number from 1
| through 366. The default number of days is 30. The
| @INFORMATION SYSTEM command reports the number of days a
| password is valid.
|
| After a password has expired, the user will be allowed to log in but
| must change the password immediately.
|
|
|
11.3.3 Disallowing Certain Passwords
| 11.3.3 Disallowing Certain Passwords
|
| You may want to make certain combinations of characters illegal for
| use as passwords. Perhaps they would be too easily guessed by an
| intruder. You can place such words in the file
| SYSTEM:PASSWORD.DICTIONARY and have them automatically matched against
| newly supplied passwords. If a match occurs, the password is denied,
| and the user must choose a new one.
|
| The following is a sample password dictionary file. Note that words
| must be placed in the file alphabetically.
|
| ABORT, S, ED, ING
| ABUSE, S, D, \ING
| ACQUIT, S, "ED, "ING
| ADMIRAL, S, 'S
|
| The first line shows the word ABORT. Other entries, separated by
| commas, indicate suffixes that are added to ABORT. So, the first
| line, in effect, contains the following words that cannot be used as
| passwords: ABORT, ABORTS, ABORTED, or ABORTING.
|
| In the second line, the backslash character (\) removes the last
| character from the base word and adds the suffix. The base word is
| ABUSE. After the final E is removed and ING is added, the word
| ABUSING is formed and cannot be used as a password.
|
| In the third line, the quote character (") duplicates the last letter
| of the word before adding the suffix; ACQUIT becomes ACQUITTED.
|
| In the final line, the apostrophe is taken as is. The base word
| ADMIRAL becomes ADMIRAL'S.

11-29
ACCESS CONTROLS
ACCESS CONTROLS

11.4 LAST LOGIN INFORMATION
11.4 LAST LOGIN INFORMATION

When users log into the system, the dates and times they last logged
in are displayed on their terminals. This information helps alert
them to instances of illegal system or account entry. For example, if
users keep track of their actual login times, they can compare those
times to the ones displayed. Then, if there is a discrepancy, they
will know the exact time that someone else logged into their directory
using their password.

| The system also provides login-failure information.
|
| Information is provided for both interactive and noninteractive
| logins. An example of a noninteractive login is one for a batch job.

11-30
ACCESS CONTROLS
ACCESS CONTROLS

11.5 PREVENTING FAST LOGINS
11.5 PREVENTING FAST LOGINS

By using the /FAST switch with the LOGIN command, users can bypass
processing of the system's and their own LOGIN.CMD and COMAND.CMD
files. Managers sometimes set up these command files to limit users'
computing environments, however. For example, sets of users may be
allowed only to read mail or run some other computer application. You
can prevent fast logins at your site by entering the following command
in the n-CONFIG.CMD file:

_______ _________________
DISABLE FAST-LOGIN-OPTION

The ENABLE FAST-LOGIN-OPTION command is in effect by default. You can
also enable and disable fast logins with the ^ESET privileged command.

_______ ______ _____
Refer to the TOPS-20 User's Guide for information on the LOGIN.CMD and
_______ ________ _________ ______
COMAND.CMD files. The TOPS-20 Commands Reference Manual describes the
LOGIN command.

| Also, with fast logins, system mail is not displayed, nor is notice of
| new mail given.
|
|
|
11.6 PREVENTING NOT-LOGGED-IN SYSTAT
| 11.6 PREVENTING NOT-LOGGED-IN SYSTAT
|
| You can prevent people who are not logged in to a system from finding
| out the usernames of people who are logged in. If your site has
| public or network access, you should disable not-logged-in SYSTAT.
| Enter the following command in the n-CONFIG.CMD file:
|
| DISABLE NOT-LOGGED-IN-SYSTAT
|
| This increases security by making it harder for intruders who have
| connected to a system but not yet logged in to find out valid
| usernames for the system. To allow the SYSTAT command when users are
| not logged in, enter the following command in the configuration file:
|
| ENABLE NOT-LOGGED-IN-SYSTAT

11-31
ACCESS CONTROLS
ACCESS CONTROLS

11.7 SECURING FILES
| 11.7 SECURING FILES
|
| You and users can restrict access to files and directories according
| to the type of access or the particular user who attempts access: The
| command @SET FILE [NO] SECURE sets a file "secure" or not secure, and
| the commands @SET DIRECTORY and @BUILD cause all new files created in
_______ ________
| the directory to be set secure. (Refer to the TOPS-20 Commands
_________ ______
| Reference Manual for details on these commands.)
|
| When a request is made to access a "secure" file, the monitor asks the
| ACJ for permission to open the file before the request is granted or
| denied. The ACJ bases its decision on the information contained in
| the ACCESS.CONTROL file, which you or users create and place in the
| same directory as files that are marked as secure. This file contains
| a list of filenames, access keywords, and usernames that have
| unrestricted access. It is important that the ACCESS.CONTROL file be
| set secure so that it cannot be changed.
|
| The format of the ACCESS.CONTROL file is:
|
| filename keyword user, keyword user,...,-
|
| Where:
|
| o filename is the name of the file to be set secure
|
| o keyword determines the type of access granted to users of
| secure files:
|
| ALL (all access)
| APPEND (append access)
| DELETE (delete access)
| NOSECURE (permission to clear the SECURE bit)
| READ (read access)
| RENAME (permission to rename the file from or to filename)
| SECURE (permission to set a file secure)
| WRITE (write access)
|
| o user is the user who is granted access
|

11-32
ACCESS CONTROLS
ACCESS CONTROLS

11-33
ACCESS CONTROLS
ACCESS CONTROLS

11.8 SECURITY HINTS
| 11.8 SECURITY HINTS
|
| Listed below are some general tips for enhancing the security of your
| TOPS-20 system.
|
Usernames
| o Usernames: No username should be used by more that one
| person at a time. It is important that each person accessing
| the system do so with a username uniquely assigned to that
| person. Sharing usernames hampers or, in some cases,
| prevents auditing of security problems.
|
Capabilities
| o Capabilities: Since a user with WHEEL or OPERATOR capability
| has the power to change many aspects of system operation, the
| WHEEL and OPERATOR capabilities should be granted to a
| minimum number of usernames on the system.
|
| A need to access files should be handled by the directory and
| user groups structure but not by granting OPERATOR
| capability.
|
| Note that it is a particularly BAD idea to have one username
| with WHEEL or OPERATOR that a number of persons use.
|
Backups
| o Backups: A "system tape" (containing the monitor, exec, user
| information, and system files from the boot structure) should
| be created once a week. Not only is this useful for hardware
| failures, but it can also provide a known secure copy of the
| monitor and all other software running on the system with
| enabled capabilities.
|
FILES-ONLY directories
| o FILES-ONLY directories: Directories on the system's PS:
| structure that are not normally used for usernames should be
| set FILES-ONLY. This prevents usernames from being created,
| which can lead to security problems.
|
OPERATOR username
| o OPERATOR username: Prevent the OPERATOR username from
| logging in interactively by removing or expiring its
| password. OPERATOR should be used to run jobs needed for
| system operator (for example, jobs under SYSJOB or PTYCON
| that are logged in when the system is reloaded).
|
| A password does not have to be set for OPERATOR in order for
| jobs to log in to OPERATOR under SYSJOB or PTYCON. Operators
| should use their own usernames to back up the system areas
| and run OPR. (The OPERATOR user can run DUMPER under PTYCON
| to save the system areas.)
|
Local Changes
| o Local Changes: It is important not to underestimate the
| positive effect that a few minor site-specific changes have
| on security. Anything that makes your system just a little
| different will slow down attempted break-ins. For example,
| change the ACJ log filename from the default.

11-34

CHAPTER 12
CHAPTER 12

THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.1 OVERVIEW
12.1 OVERVIEW

The Common File System (CFS) is a feature of TOPS-20 that allows users
from more than one system to simultaneously access files. Any
structure in the CFS configuration can be made available to any user
for reading or writing.

Each TOPS-20 system in the CFS configuration has its own operating
system, main memory, system structure, console, unit-record devices,
and processes to be scheduled and run. But the systems are linked
through a shared file system. This unified file system can be
composed of all the disk structures on all systems. These structures
appear to users as local to their own systems.

The main features of CFS are:

o It increases file accessibility. For example, if a system is
down for maintenance, users can log onto another system and
still access all files that do not depend on the down system
for access.

o It lets you adjust loads on systems by reassigning users as
loads require. (Or, users themselves may be allowed to
switch systems as they see fit.) These changes need not
result in file-access limitations.

o It lets you reduce the time that would be involved in
maintaining duplicate sets of files.

o It lets you save disk space by minimizing duplication of
files on different systems.
|
| CFS (with Cluster GALAXY software) also lets users send jobs to
| printers connected to any system in the configuration.

12-1
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.1.1 CFS HARDWARE
12.1.1 CFS HARDWARE

The following are typical CFS configurations:

+--------------+ +--------------+
| | | |
SYSTEM ----| DECSYSTEM-20 |-------DISK-------| DECSYSTEM-20 |-- SYSTEM
STRUCTURE | |-------DISK-------| | STRUCTURE
| +------| +------+ |
| | CI20 | | CI20 | |
+--------------+ +--------------+
\\ //
\\ //
\\ //
\\ //
\\ //
\\ //
\\ //
+----------------+
| |
| STAR |
| |
| COUPLER |
| |
+----------------+
|| ||
|| ||
+----------------+---DISK
| |---DISK
| HSC 50 |---DISK
| |---DISK
+----------------+

Figure 12-1: Two Systems with Massbus Disks and HSC50-based Disks
Figure 12-1: Two Systems with Massbus Disks and HSC50-based Disks

12-2
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

+--------------+ +--------------+
| | | |
SYSTEM ----| DECSYSTEM-20 |-------DISK-------| DECSYSTEM-20 |-- SYSTEM
STRUCTURE | |-------DISK-------| | STRUCTURE
| +------|-------DISK-------+------+ |
| | CI20 |-------DISK-------| CI20 | |
+--------------+ +--------------+
\\ //
\\ //
\\ //
\\ //
\\ //
\\ //
\\ //
+----------------+
| |
| STAR |
| |
| COUPLER |
| |
+----------------+

Figure 12-2: Two Systems with Massbus Disks
Figure 12-2: Two Systems with Massbus Disks

____ _______
Star Coupler

The star coupler provides the physical interconnection for the CI
cables among DECSYSTEM-20s and HSC50s. The maximum distance between a
system and the star coupler is 45 meters.

A DECSYSTEM-20 can be connected to just one star coupler. That is, it
can be part of only one CFS cluster.

__
CI

The Computer Interconnect (CI) bus is the communications link used by
CFS. It also connects systems to HSC50-based disks (RA60s and RA81s).
In addition, it provides access to massbus disks for systems without a
direct connection to those disks, for example, to another system's
system structure.

Each system has four communications links to the star coupler. Two of
them are for transmitting data and the other two are for receiving
data. The redundant CI connections are used for increased
availability and performance. When one of the connections has failed
or is in use, the CI microcode chooses the other one for data
transmission. At start-up, TOPS-20 verifies that at least one set of
transmit and receive connections is working.

12-3
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

____
CI20

The CI20 port adapter provides the interface between the DECSYSTEM-20
and the CI bus. Only one CI20 is allowed per system.

_______ _____
Massbus Disks

Multisystem access may be granted to all massbus disks.

It is recommended that massbus disks intended to be shared be
dual-ported between two DECSYSTEM-20s (drive port switches placed in
the A/B position). With a two-system CFS cluster, this avoids the
___________
overhead involved in file-server activity, as described later in this
section. However, the systems must be able to communicate with each
other over the CI; they must be connected to the same star coupler.
_____
Otherwise, neither system will be allowed access to the disk. Thus,
___ _________ ______________ ___ ___ _________
the following configurations are not supported:

+--------------+ +--------------+
| | | |
| G | | H |
| |-------DISK-------| |
| | (A/B) | |
| | | |
+--------------+ +--------------+

+--------------+ +--------------+ +--------------+
| | | | | |
| G | | H | | I |
| |-------DISK-------| | | |
| | (A/B) | | | |
| | | | | |
+--------------+ +--------------+ +--------------+
| |
| |
| |
| |
| |
| |
--------------------------------- CI

12-4
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

+--------+ +--------+ +--------+ +--------+
| | | | | | | |
| G | | H | | I | | J |
| | | |-------DISK-------| | | |
| | | | (A/B) | | | |
| | | | | | | |
+--------+ +--------+ +--------+ +--------+
| | | |
| | | |
| | | |
| | | |
------------------------- CI ------------------------ CI

In the first two figures, systems G and H are not joined in a CFS
configuration. The same applies to systems H and I in the third
figure. TOPS-20 maintains the integrity of data on shared disks by
ensuring that the systems can, over the CI, coordinate accesses to
those disks.

______
Massbus disks not directly connected to a system are called "served
_____
disks" because TOPS-20's MSCP (Mass Storage Control Protocol)
file-served facility makes this "outside" access possible. To enable
an outside path to a massbus disk, that is, to make it a served disk,
enter an ALLOW command in the n-CONFIG.CMD file, on a system to which
the disk drive is connected, in the form:

ALLOW serial number

The drive type is one of the following: RP06, RP07, or RP20. You can
obtain the serial number with the command:

____ _____________ _______________
OPR>SHOW CONFIGURATION DISK-DRIVE

Note that TOPS-20 creates an RP20 serial number by adding 8000 to the
disk drive unit number. Therefore, RP20 unit numbers should be unique
among CFS systems.

| To disallow access to a served disk that was allowed access, enter the
| following command in the n-CONFIG.CMD file:
|
| RESTRICT serial number
|
| Disks are RESTRICTED by default if you do not specify ALLOW commands.

NOTE

Disks that make up the system structure must not be
dual ported to another TOPS-20 system.

12-5
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.1.2 CFS SOFTWARE
12.1.2 CFS SOFTWARE

Intersystem communication is an integral part of CFS. When TOPS-20
starts up, it makes a CFS connection with each TOPS-20 system that is
already running. This establishes the contact necessary for
intersystem file-system management.

In reality, only one system writes to a 256K section of a file at a
time. When a system needs write access to a file section, it
broadcasts a request for that resource to all systems it has
established contact with. If another system already owns the desired
write access, that system will respond negatively. Clearance will be
granted to the requesting system only after the other system has
completed the write operation by writing the data back to disk from
its memory. Thus, systems negotiate for write access to files and
keep each other informed of the state of the disks that they share.
This ensures the integrity of data on those disks.

Because intersystem communication is vital to CFS operations, the
systems stay alert to CI problems and to other indications that they
may have lost contact with each other. Section 12.11.1, Communication
Problems, discusses the actions that systems take when there is a
breakdown in communications.

The INFORMATION CLUSTER command displays the names of HSC50s and CFS
systems that are currently accessible.

____ ___ ____
DATE and TIME

When a CFS system starts up, it takes the date and time from the
systems that are already running. The operator is not prompted for
this information. Instead, the system types a message similar to the
following on the operator's terminal:

The date and time is: Wednesday, 11-MAY-1988 9:38AM

This typeout serves as a check on the date and time. If no other
system is running, the operator is prompted for the information.

When the date and time are changed on any CFS system, such as with the
^ESET command, all other systems are notified so that they can
re-synchronize. This synchronization ensures that the creation date
and time of files written from one system are consistent with the
other CFS systems. Otherwise, many programs that use this information
could malfunction.

12-6
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.1.3 CFS USERS
12.1.3 CFS USERS

CFS is transparent to users:

o Users are normally unaware that someone from another system
may be accessing a file at the same time that they are,
except in such cases as the following. A file being read on
system "A" will prevent its being renamed on system "B."

o Users are not required to know about the CFS configuration.
Specifically, they do not need to know how massbus disks are
ported. To access files, all they need to know are structure
names, as on non-CFS systems.

The INFORMATION CLUSTER command lets users know what HSC50s and
TOPS-20 systems are currently accessible to their systems.

12.1.4 CFS and DECnet
12.1.4 CFS and DECnet

A CFS configuration differs from a DECnet network. Although a CFS
configuration comprises multiple independent systems, the systems
share a unified file system and cooperate in its operation. They
function more as a single system than as systems merely communicating.
If the optional DECnet-20 software is installed, each CFS system
running DECnet is a DECnet network node with its own node name.

The files in CFS disk structures may be accessible to remote systems
by way of such DECnet facilities as NFT. However, a node name is
needed to access files in this way. CFS users, on the other hand, do
not need to specify node names.

All systems in a CFS configuration must be TOPS-20 systems. In a
DECnet network, however, other systems that support DECnet can be
included.

DECnet on a system allows access to other CFS clusters as well as
DECnet communication between systems in a cluster (for example, with
the SET HOST command).

12-7
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

Table 12-1: Comparison of CFS and DECnet
Table 12-1: Comparison of CFS and DECnet

__________________________________________________________________

Characteristic CFS DECnet
Characteristic CFS DECnet
__________________________________________________________________

Multiple systems X X

TOPS-20 systems only X

One file system X

Node name in file spec X

DECnet software X

CI X X

NI X
__________________________________________________________________

12.1.5 CFS and TIGHTLY-COUPLED SYSTEMS
12.1.5 CFS and TIGHTLY-COUPLED SYSTEMS

A CFS cluster also differs from tightly-coupled multiprocessing
environments. Each CFS system has its own main memory, which is not
shared with another system. It also has its own system structure for
booting and swapping and may have its own public structure for logging
in. Also, CFS systems do not perform automatic load balancing. That
is, the CPUs do not relieve each other of processing during high job
loads. All jobs, including batch jobs, run only on the computer that
the user logs onto.

12.1.6 Limitations
12.1.6 Limitations

CFS does not coordinate use of the following facilities across
systems: IPCF and OPENF OF%DUD. As an example, a DBMS application
cannot span multiple systems, because DBMS uses the OPENF OF%DUD
facility. Therefore, such applications should be restricted to a
single system. Attempts to cross systems using these facilities will
generate error messages.

CFS allows for shared disk files and line printers. However, it does
not provide for shared magnetic tapes.

12-8
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.1.7 "Cluster Data Gathering"
12.1.7 "Cluster Data Gathering"

The "cluster data gathering" system application (CLUDGR) is enabled by
default in the n-CONFIG.CMD file. This "SYSAP" collects
cluster-related data so that, for example:

o Users can obtain information on remote systems in the cluster
by way of the SYSTAT command.

| o Users can send messages throughout the cluster with the SEND
| command.

o Operators can obtain scheduling information on remote systems
(SHOW SCHEDULER), receive structure status information from
system responses during remote structure dismounts, and send
messages to users throughout the cluster (^ESEND and SEND).

o System programmers can use the INFO% monitor call to obtain
information on remote cluster systems. (As described in
Section 11.1, you can control access to the INFO% monitor
call through the access control program.)

You can disable and enable user, operator, and programmer CLUDGR SYSAP
functions in the n-CONFIG.CMD file with the following commands:

DISABLE CLUSTER-INFORMATION
DISABLE CLUSTER-SENDALLS

ENABLE CLUSTER-INFORMATION
ENABLE CLUSTER-SENDALLS

NOTE

The CLUDGR SYSAP functions cannot be disabled for the
GALAXY components.

During timesharing, the operator can disable and enable these same
functions with the following privileged commands:

^ESET [NO] CLUSTER-INFORMATION
^ESET [NO] CLUSTER-SENDALLS

12.1.8 Cluster GALAXY
12.1.8 Cluster GALAXY

GALAXY is the TOPS-20 batch and spooling subsystem. In a cluster, it
lets operators:

o Dismount a structure from a single terminal in a cluster even
if the structure is mounted on more than one system in the
cluster. The dismount with removal process is automated.

12-9
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

o Mount structures on a remote system in the cluster.

o Set a structure exclusive from a single terminal in a cluster
even if the structure has been mounted on more than one
system in the cluster. This process is automated.

o Send messages to all users on remote systems in the cluster.

| o Control cluster printers

o Obtain remote information through most of the SHOW commands.

o Obtain the status of inter-system GALAXY DECnet connections.

"Cluster GALAXY" requires DECnet, TOPS-20 version 7, and GALAXY
version 6.

You can disable cluster GALAXY on one or more systems by way of the
GALGEN dialog. This dialogue can be run during or after system
installation, and then GALAXY must be rebuilt. However, with the
feature disabled, none of the remote functions listed above are
available; the operating environment is as it was in GALAXY version 5,
with TOPS-20 version 6.1. For example, to dismount a shared
structure, the operator had to give commands from a terminal on each
system on which the structure was mounted, and there was not a great
deal of remote information to help the operator with this activity.

This chapter assumes that the feature is enabled.

12.2 PLACEMENT OF FILES
12.2 PLACEMENT OF FILES

This section offers guidelines for arranging files on CFS systems for
maximum performance and efficiency.

12-10
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.2.1 Update Files
12.2.1 Update Files

Simultaneous shared writing to a file from multiple systems incurs the
most overhead of any CFS file access operation. This is because
systems involved in shared writing spend time seeking and granting
write permission and coordinating their moves in other ways.
Therefore, you might want to place the involved users on the same
system.

12.2.2 Files on Served Disks
12.2.2 Files on Served Disks

For optimum performance, you should not place on served disks files
that require frequent access from multiple systems. This applies to
both reads and writes. MSCP file-server operations incur considerable
overhead, because the system with the direct connection acts as a disk
controller for the accessing system. Therefore, such files should
reside on HSC50 disks or, in a two-system CFS configuration, on
massbus disks dual ported between systems.

12.2.3 Mail Files
12.2.3 Mail Files

By default, users' mail files are created and updated in their
logged-in directories on the public structure. To access this mail,
users log in and issue appropriate mail commands. They may have to go
through this login procedure for every system that contains mail for
them. You can change this default arrangement and simplify matters
for the CFS user who has accounts on multiple systems. By redefining
the systemwide logical name POBOX:, as described in Section 3.3.9, you
can establish a central location on a sharable structure for all mail
files in the CFS configuration. Then, no matter where users log in,
the mail facility sees an accumulation of mail that could have been
addressed to them at any system in the configuration. Mail is no
longer isolated on individual public structures.

An added advantage to redefining POBOX: is that public structures do
not fill up with mail files.

You must create a directory on the structure defined by POBOX: for
every user in the CFS configuration who is to receive mail.

12-11
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.2.4 Sharing System Files
12.2.4 Sharing System Files

Most of the files that normally reside on system structures can be
moved to a shared structure. Rather than duplicate files in such
areas as SYS: and HLP: across systems, you can keep one set of these
files on a shared structure. This saves disk space and eases the task
of maintaining the files. Also, time and tape are saved during DUMPER
backup and restore operations. Because system files are primarily
read and not often updated, system performance does not suffer because
of this file sharing, provided the structure is not on a server disk.
If you consolidate system files, remember to include in the
definitions for the systemwide logical names the structures that
contain the files. For example, if the SYS: files reside on the
structure COMBO:, the definition for SYS: would be:

______ ____ ___________________ _____________________
DEFINE SYS: (AS) COMBO:, COMBO:,-
__________________ __________________
MAIN:, MAIN:

where:

MAIN: is the name of a system structure

You should define structures in this way on all the systems, giving
the appropriate system structure name. Make sure that the shared
structure or structures are mounted UNREGULATED so that users will be
able to access the files without having to give a MOUNT command.

The drawback to sharing system files is that if there is trouble with
the shared structure, users on all systems suffer.

Most of the SYSTEM: files must remain on the system structures, so
sharing these files is not recommended.

________ _____
START-UP FILES

Certain files must remain on each system structure. These files are
involved in system start-up and are required before a non-system
structure is made available to a system. The following files should
remain in each area:

7-CONFIG.CMD
7-PTYCON.ATO
7-SETSPD.EXE
7-SYSJOB.EXE
7-SYSJOB.RUN
ACCOUNTS-TABLE.BIN
CHECKD.EXE
DEVICE-STATUS.BIN
DUMP.EXE
ERRMES.BIN
EXEC.EXE

12-12
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

HOSTS.TXT
IPADMP.EXE
IPALOD.EXE
KNILDR.EXE
MONITR.EXE
MONNAM.TXT
TGHA.EXE

In addition, all the GALAXY files should remain in each area.
These files come from the GALAXY saveset on the TOPS-20 Distribution
_______ __ _____ _ ____________ _____
Tape. (Refer to the TOPS-20 KL Model B Installation Guide.)

Command files that are used at your installation during start-up also
should be kept on separate system structures. These files include
SYSTEM.CMD and NETWORK.CMD.

12.3 LOAD BALANCING
12.3 LOAD BALANCING

This section discusses the distribution of jobs across CFS systems.

12.3.1 Dedicating Systems
12.3.1 Dedicating Systems

One way to balance loads is to establish the types of jobs that will
run on particular systems. For example, you might relegate batch jobs
to one system, freeing other systems to run interactive jobs
unimpeded. To encourage users to adopt this arrangement, you could
give batch jobs the lowest priority on all but the batch-designated
system. Users will have to wait a relatively long time for completion
of batch jobs on non-batch systems. Refer to Section 10.2, SCHEDULING
LOW PRIORITY TO BATCH JOBS, for further information.

Conversely, on the batch system, you could accord batch jobs the
highest priority. Refer to Section 10.1.4, Procedures to Turn On the
Class Scheduler, for details. Dedicating a system in this manner is
especially useful when there are many long-running batch jobs at an
installation.

Another suggestion is to put software development jobs on one system
and production jobs on another. Also, you may want to keep one system
lightly loaded for critical jobs.

DBMS applications and programming applications requiring IPCF
facilities must be confined to one system. These are other items to
consider if you choose to establish certain uses for particular
systems.

___ ____
Keep in mind that users must log onto the systems that are to run
their particular jobs. This applies to batch jobs also (without

12-13
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

DECnet). Batch jobs must be submitted by a user logged in on the
system where they are to run. The control and log files may reside on
shared disks.

12.3.2 Assigning Users to Systems
12.3.2 Assigning Users to Systems

In the CFS environment, much of the load balancing is expected to be
performed by users. The systems, for example, do not detect that one
CPU is overburdened and that another one is underutilized and,
accordingly, reassign users' jobs. Instead, users themselves could
determine whether or not they should log off a system and log onto
another one when system response is slow. Such user tools as the
SYSTAT and INFORMATION SYSTEM commands and the CTRL/T function can
help users in this area. These tools report on the current state of a
system. Among the items reported are the number of jobs running on a
system, load averages, the current setting of the bias control "knob,"
| and whether batch jobs are assigned to a special class. This
| information can be obtained for all systems in the configuration, not
| just for the user's logged-in system.

If you choose this load balancing scheme, you should create
directories for all users on all the system structures in the CFS
configuration. Also, directory usernames should be unique throughout
the configuration, as described below. Then, users can log onto any
system with no problem.

_________
USERNAMES

Directory usernames should be unique throughout the CFS configuration.
For example, there should be only one user with the username
at an installation. This lets users access system resources without
encountering password-related obstacles or causing security breaches.

If two users on different systems have the same usernames but
different passwords, their passwords will be invalid when they switch
systems. If these same users should by chance have the same
passwords, they will have complete access to each other's files when
they switch systems. Also, if a structure is mounted on both systems
as domestic, neither user will have to give a password when accessing
the directory on that structure that has their username. (Refer to
Section 4.5.7, Mounting Structures from Another Installation, for a
discussion of foreign and domestic structures.)

_________ ___ ____ ______
DIRECTORY AND USER GROUPS

To facilitate user access to CFS files, you could make directory and
user group numbers consistent on all structures. That way, users
could change structures or systems and their access attempts would
have predictable outcomes.

12-14
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.4 STRUCTURE NAMES
12.4 STRUCTURE NAMES

Because the structures on all systems are part of a unified file
system, structure names must be unique throughout the CFS
configuration.

If it is necessary to mount structures with duplicate names, the
operator should mount one of the structures using an alias. (Refer to
Section 4.5.2, Mounting Structures Having the Same Name.) The system
recognizes a structure by its alias, which is the same as the
permanent structure identification name, unless otherwise specified.
Note that everyone throughout the CFS configuration must refer to a
structure by the same alias.

12.5 SYSTEM LOGICAL NAMES
12.5 SYSTEM LOGICAL NAMES

Logical names are implemented differently from structure names and
their aliases. Logical names are local definitions that need not be
unique nor consistent throughout the CFS configuration. Thus, the
same logical name on two different systems can refer to two completely
different disk areas. However, because users are likely to be mobile,
systemwide logical names should be consistent across systems. This
will avoid confusion for users who switch systems.

Refer to Section 3.3, SYSTEM-LOGICAL NAMES, for further information.

12.6 SHARING STRUCTURES AMONG SYSTEMS
12.6 SHARING STRUCTURES AMONG SYSTEMS

By default, all structures in the CFS configuration are accessible to
all systems, provided outside paths have been established for massbus
disks where necessary, using the ALLOW command (refer to Section
12.1.1, CFS HARDWARE). It is necessary to "mount" a structure on any
system that is to access files on it, however. That is, the operator
or a user on that system must issue a MOUNT command for the structure.
| (There can be up to 64 structures online on one system.) After a
structure is mounted on a system, users can access it as on non-CFS
systems. Users have automatic access to their public structure files,
as on non-CFS systems.

If a structure has been restricted to a system through previous use of
the operator command, SET STRUCTURE str: EXCLUSIVE, it can be made
sharable again with the SET STRUCTURE str: SHARED command. The
operator issues this command from a terminal running OPR on the system
that has exclusive use of the structure. Then, MOUNT commands can be
issued for the structure that has been made sharable. The default
setting for structures is sharable.

12-15
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

The operator command, SHOW STATUS STRUCTURE, indicates the shared or
exclusive status for all structures known to a system.

_________ __________
STRUCTURE ATTRIBUTES

The operator specifies attributes for a structure with the SET
_______ __________ _______
STRUCTURE command, as described in the TOPS-20 Operator's Command
________ _________ ______
Language Reference Manual. They are permanent settings that do not
revert to default values after system crashes and reloads.

Note that all systems need not have the same attributes in effect for
a structure. For example, one system can have a structure mounted as
foreign and regulated, and another system can have the same structure
mounted as domestic and unregulated. Except for SHARED and EXCLUSIVE,
attributes are on a single-system basis only.

12.6.1 Sharing System Structures
12.6.1 Sharing System Structures

Bear in mind that when system structures are shared, privileged users
can create privileged accounts on any system structure, with the
^ECREATE command. This may or may not be desirable.

12.6.2 Sharing the Login Structure
12.6.2 Sharing the Login Structure

In a CFS-20 cluster, it may be advantageous to set up a homogeneous
environment where all user accounts reside on a shared "login
structure". Then, you do not need to maintain an account on every
system to which a user has access.

12.6.2.1 Creating the Login Structure
12.6.2.1 Creating the Login Structure - To create this shared
structure, give the following command to the CHECKD program for every
system in the cluster:

______ _______________ ____ ________
CHECKD>ENABLE LOGIN-STRUCTURE(FOR STRUCTURE)str:(FOR CPU)cpu

where: str is the name of the login structure and cpu is the system's
CPU serial number. The default serial number is the current system's.

This command adds the CPUs' serial numbers to the login structure's
home blocks. The following command displays all the serial numbers
that were entered into the blocks:

12-16
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

____ ____________________
CHECKD>SHOW (INFORMATION FOR) LOGIN-SERIAL-NUMBERS (FOR STRUCTURE)
_________
str:

where: str is the name of the login structure

You should create a directory on this structure for each user in the
cluster. (You can also put any other kind of directory on the login
structure.) Users' LOGIN.CMD files and their .INIT files for various
system programs should reside in these directories.

12.6.2.2 Enabling "Login Structure"
12.6.2.2 Enabling "Login Structure" - The system looks for user
accounts on the login structure rather than on the boot structure when
you enter the following command in the n-CONFIG.CMD file:

ENABLE LOGIN-STRUCTURE

12.6.2.3 Disabling "Login Structure"
12.6.2.3 Disabling "Login Structure" - You can disable the "login
structure" feature with the following commands:

____________ ____
n-CONFIG.CMD file:

DISABLE LOGIN-STRUCTURE

______ _______
CHECKD program:

_______ _______________ ____ ________
CHECKD>DISABLE LOGIN-STRUCTURE(FOR STRUCTURE)str:(FOR CPU)cpu

where: str is the name of the shared structure and cpu is the
system's CPU serial number. The default serial number is the current
system's.

These commands cause the system to look for user accounts on the boot
structure, which is the default condition.

12.6.2.4 PS: and BS: Directories
12.6.2.4 PS: and BS: Directories - Before you enable the "login
structure" feature, the public structure (PS:) is the boot structure
(BS:), and is also known as the system structure.

After you enable the feature, the system considers PS: to be the
login structure, the structure that contains all the user login
directories.

12-17
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

The special system directories, described in Section 3.2, must remain
on BS:, although you may choose to move many of their files to other
directories. However, the files listed in Section 12.2.4 must remain
on the boot structure in :

Also, the GALAXY components write files to SPOOL:, which the system
defines at startup to be BS:.

NOTE

Except where noted, this manual assumes that you have
___
not enabled the "login structure" feature.

12.7 RESTRICTING STRUCTURES TO ONE SYSTEM
12.7 RESTRICTING STRUCTURES TO ONE SYSTEM

There may be times when you want to restrict use of a structure to a
particular system. Such a structure might be used for DBMS
applications (refer to Section 12.1.6, Limitations), or security
measures may call for restricted use. For whatever reason, the
operator restricts a structure with the following command:

___ _________ ____ ______________
OPR> SET STRUCTURE str: EXCLUSIVE

When the operator gives this command, the system first checks to see
that the structure is not in use on other systems. If it is, the
operator is given a list of those systems and asked whether or not
this system should proceed with an automatic remote dismount of the
structure from those systems (with the NO-REMOVAL option). This
information and automatic dismount requires cluster GALAXY to be
enabled. Ideally, the operator should beforehand follow the normal
dismount procedure of making the structure unavailable to new users
and notifying existing users of the pending dismount. The structure
should be kept unavailable for all systems except the exclusive one so
that the structure will not be inadvertently shared when the owning
system crashes.

After a structure has been dismounted from other systems, the SET
STRUCTURE EXCLUSIVE command can take effect. It remains in effect on
the system, as do all SET STRUCTURE specifications, throughout crashes
and reloads. If users give the MOUNT command for a structure that is
exclusive to another system, an error message will be issued,
indicating that the structure is unavailable.

Note that any system can have exclusive use of any sharable structure
except another system's system structure.

_______ __________ _____
Refer to the TOPS-20 Operator's Guide for details on setting
structures exclusive.

12-18
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.8 DISMOUNTING STRUCTURES
12.8 DISMOUNTING STRUCTURES

When issuing a DISMOUNT command for a structure, operators have the
option of specifying that the structure be physically removed from a
disk drive. In the CFS environment, however, the system first ensures
that the structure is not in use on other systems. If a structure is
mounted on another system, the operator is notified and must go
through the normal procedure of dismounting the structure (with the
NO-REMOVAL option) from that system.

Note that with cluster GALAXY enabled, the operator can dismount
structures remotely by performing all activities from an OPR terminal
on the local system. The operator does not need to log onto any other
system.

Throughout the dismount process, the operator receives various
informational messages as well as error messages if, for example, the
system cannot get an exclusive lock on the structure by way of the
ENQ% monitor call or communicate with nodes on which the structure is
mounted. (The system cannot communicate with nodes that have the
cluster GALAXY feature disabled.)

_______ __________ _____
Refer to the TOPS-20 Operator's Guide for details on dismounting
structures.

The default setting on CFS systems is for a structure to be dismounted
with the no-removal option.

Sometimes the system instructs the operator to dismount structures.
This can occur for the following reasons:

o The operator attempts to shut down a system.

o The operator attempts to make the CI unavailable to a system.
|
| o A system has been granted exclusive use of a structure.
|
| o A structure has been physically dismounted from another
| system.
|
| Refer to Sections 12.7, 12.9, and 12.12 for details.
|
| These dismount instructions appear if you have included the ENABLE
| JOB0-CTY-OUTPUT command in the n-CONFIG.CMD file.

12-19
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.9 MAKING THE CI UNAVAILABLE TO A SYSTEM
12.9 MAKING THE CI UNAVAILABLE TO A SYSTEM

Ordinarily, you need do nothing at all to operate the CI. However,
you may need to disengage a system from the CI so Field Service
personnel can diagnose and/or correct problems with the CI20 or the
HSC50. Or, you may wish to remove a system from the CFS
configuration. At those times, you should instruct the operator to
make the CI unavailable by means of the SET PORT CI UNAVAILABLE
_______ __________ _____
command. (Refer to the TOPS-20 Operator's Guide for details.)

When the CI is unavailable to a system, users cannot access
multi-access disks (dual-ported disks, HSC50-based disks, or served
disks on other systems). These disks rely on the CI to coordinate
accesses and/or to transmit data. Served disks on the system
disengaging from the CI will be unavailable to other systems.
Dual-ported massbus disks in the A/B position will have to be powered
down and switched to one system.

When the operator gives the SET PORT CI UNAVAILABLE command, the
system indicates the structures that need to be dismounted and the
disk drives that need to be made unavailable. The operator is advised
to follow the normal procedures of forewarning users before
dismounting structures and making disk drives unavailable. The
command option to forcibly disengage a system from the CI should be
reserved for emergencies. If the operator determines that disengaging
from the CI will be too disruptive to users, the operator has the
option of aborting the procedure.

To put the CI back in operation, the operator gives the command:

___ ____ __ ______________
OPR>SET PORT CI AVAILABLE

The operator is then asked if any other TOPS-20 system is running on
the CI. If yes, the system rejoining the CFS configuration must be
rebooted. If no, the CI20 will be reloaded and started. If the
operator answers "no" and another TOPS-20 system is found after the
CI20 has started, a CFRECN BUGHLT is issued on processors with lower
serial numbers than the system joining the cluster and on this
processor also, if there's a system in the cluster with a higher
serial number. (See Section 12.11.1 for details.) After the system
rejoins the configuration, structures that were affected when the CI
was made unavailable will need to be remounted.

12.10 USING DUMPER
12.10 USING DUMPER

CFS offers operators and users flexibility in saving and restoring
disk files. The only restriction is that DUMPER must be running on a
system to which tape drives are attached. Tape drives are not served
through CFS.

12-20
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.11 ERRORS
12.11 ERRORS

This section discusses the actions you or the operator take when
errors occur in the CFS environment. It also describes how CFS
systems react to various errors. Note that there is no single
hardware or software point that can disable the whole configuration.
For example, systems can start up or crash with little impact on other
systems.

12.11.1 Communication Problems
12.11.1 Communication Problems

CFS systems are sensitive to breaks in communication, whether they are
caused by CI20 errors or system crashes. Because the data integrity
of shared structures depends on unbroken intersystem contact, the
systems take quick action to prevent data corruption. Therefore, you
may observe any of the following when systems lose contact with each
other. These should be rare occurrences.

o For a period of time calculated as 5 seconds per node (hosts
and HSCs), no system in the configuration can access any
____________ _____
multi-access disks (dual-ported disks, HSC50-based disks,
served disks on other systems).

This interval allows each system to check that its own CI20
and segment of the CI bus are working. Most likely, some
system's CI20 microcode has stopped and is automatically
reloaded during the interval, or a system has crashed.
(There may be other, unpredictable reasons for CI
disruption.) Jobs that were accessing multi-access disks are
suspended until data integrity is assured.

If the CI20 and CI bus are working before the end of the
interval, the system can resume accessing all multi-access
disks except server disks on a crashed system.

o A system crashes with a KLPNRL BUGHLT. This happens if the
CI20 microcode takes longer to reload than 10 seconds. This
BUGHLT is expected to occur rarely, because the microcode
should be reloaded within a couple of seconds.

12-21
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

_____
o If communication resumes after the interval mentioned at the
beginning of this section, without the faulty system having
crashed and restarted, the system with the lower serial
number crashes with a CFRECN BUGHLT message as the faulty
system tries to establish contact with each running system.
That is, a system joining the cluster illegally will crash
any system already in the cluster with a lower CPU serial
number. The node itself will crash if there is already a
node in the cluster with a higher CPU serial number. For
example, this occurs when the SET PORT CI AVAILABLE command
has caused communication to resume incorrectly due to
operator error, as described in Section 12.9, MAKING THE CI
UNAVAILABLE TO A SYSTEM.

With such a delayed reconnection, a system is likely to
contain old, invalid information about the status of
multi-access disks. This is because other systems are
allowed to access the disks after the interval, believing a
faulty system is no longer running. Therefore, systems are
selected to crash so that a fresh database can be established
for the disks when the systems restart.

_______
EXAMPLE

There are four systems in a cluster with serial numbers one
through four:

System Serial Number

A 1
B 2
C 3
D 4

System B leaves the cluster and then tries to rejoin after
the delay allowance has expired. System A crashes because
its serial number is lower than system B's. System B crashes
when it tries to establish contact with either systems C or
D, whose serial numbers are higher than B's. Systems C and D
remain running.

12-22
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

__ _______
AT STARTUP

Sometimes, communication problems begin at system startup. A system
that has just started up tries to communicate with each TOPS-20 system
and HSC that is already running. After the SETSPD program sets the
systemwide defaults, a system joining the CFS cluster checks to make
sure that:

o Its own CI20 is working. If there is any malfunction, the
"CFS joining" process is aborted. The system makes no
further attempts to communicate with other CFS nodes and
remains outside the CFS cluster.

o Its segment of the CI bus is working.

If the areas above are satisfactory, the system starting up then
checks to see if, for each cluster node:

o The CI20 at the remote node is in maintenance mode (TOPS-20
nodes only, not HSCs). If so, the system knows that it
cannot communicate with that node and tries to establish
contact with the next node.

o Its own CI20 driver has created a system block for the remote
node. The driver creates this block when the remote system
responds to its request for recognition. The system block
allows for a virtual circuit to be established between the
two systems, over which inter-node data and messages are sent
on the CI. If the block does not yet exist, the system sends
a message to the CTY so that the operator can take
appropriate action on the remote node. This situation
usually indicates a hardware problem with the remote system's
CI20.

If a system block has been created for a remote TOPS-20 node, the
system tries to establish a CFS connection with that node by way of
the virtual circuit. It is through CFS connections that systems
communicate in order to coordinate access to shared disks. If the
attempt fails, a message is sent to the CTY for operator action. This
situation usually indicates a software problem, most likely that
TOPS-20 is not running at the remote node.

| If the attempt at communication is successful, a confirming BUGINF is
| sent to the starting system's CTY.

A system starting up makes these communication checks for every other
node in the cluster.

_______ __________ _____
Refer to the TOPS-20 Operator's Guide for details on the operator
| information and error messages.

12-23
THE COMMON FILE SYSTEM
THE COMMON FILE SYSTEM

12.11.2 Massbus Problems with Dual-Ported Disk Drives
12.11.2 Massbus Problems with Dual-Ported Disk Drives

Dual-ported disk drives are accessed by each system through the
massbus hardware connections. However, if for some reason a massbus
path becomes unavailable to a system, the other system, with working
massbus connections, can provide access to the drives affected, with
the MSCP file server. The disks become "served."

The operator enables this facility by powering down the disks and
flipping the drive port switches from the A/B position to the position
that corresponds to the servicing system. Then the operator must
reboot the system with the faulty massbus link. These procedures are
required because a running system will never invoke the MSCP server
after identifying a massbus path for a disk. It is assumed that an
ALLOW command has been entered in the n-CONFIG.CMD file for the disk
drives, as described in Section 12.1.1, CFS Hardware.

The operator returns the switches to the A/B position when the massbus
problem is corrected. The PHYTPD BUGINF is then issued to confirm
that the massbus will now be used for data transmission.

12.12 SHUTTING DOWN A CFS SYSTEM
12.12 SHUTTING DOWN A CFS SYSTEM

When an operator issues the ^ECEASE command to shut down a system,
outside jobs that may be accessing the system's served disks do not
hang, with the following procedure. If any served disks have been
mounted from other CFS systems, the operator is warned to check those
systems for possible structure dismounting instructions.

At the other systems, meantime, if any served disks are mounted on the
system shutting down, the operator is warned of the pending shutdown
and is advised to dismount the structures listed.

In a CFS-20 cluster, a shutdown on one system causes "system going
down" messages to be transmitted to all systems in the cluster at the
sixty-minute, five-minute, and one-minute marks. For example, if SYSA
is shutting down, the following messages appear clusterwide:

[System SYSA going down in 60 minutes at 1-Dec-87 16:29:22]

[System SYSA going down in 5 minutes at 1-Dec-87 16:29:22]

[System SYSA going down in one minute!!]

12-24

CHAPTER 13
CHAPTER 13

LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

13.1 OVERVIEW
13.1 OVERVIEW

_____ ____ _______
A local area network is a collection of computers and their resources
that are linked together in a small geographic area, such as a college
___
campus or a large building. Local Area Transport (LAT) software
________ _______
enables special-purpose computers to be used as terminal servers in
such a network. With LAT software, user and application terminals
____ _______
that would otherwise be individually wired to host systems
(DECSYSTEM-20s, for example) are instead connected directly to a LAT
terminal server. The server, in turn, is linked to one or more hosts
by way of the Ethernet Network Interconnect cable (NI), as shown
below:

+-------+ +-------+
| LAT | | LAT |
| HOST | | HOST |
| | | |
+---0---+ +---0---+
| |
| |
| |
NI ===================0==================0============0=======
|
|
|
+---0---+
Application Terminal -------| LAT |
User Terminal -------|SERVER |
User Terminal -------| |
+-------+

Figure 13-1: A LAT Network
Figure 13-1: A LAT Network

A LAT host might be a TOPS-20, VMS, or RSX-11 system. The LAT server

13-1
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

is any NI-based terminal server.

An application terminal is a device under the control of an
application process on the host. A printer is an example of an
application terminal. An application process such as LPTSPL requests
a connection to the LAT server when users want access to the device.
The type of application terminal referred to in this manual is a LAT
printer. Section 3.7 contains further information on LAT printers.

The main features of LAT servers are:

o Users can connect to any NI host that supports the LAT
protocol, and it appears to them that their terminals have
direct connections to those hosts. Connections between LAT
________
terminal users and hosts are called sessions. There can be
up to 128 sessions on a TOPS-20 host.

o By requesting multiple host connections, a LAT terminal user
can enable multiple sessions at one host or at several hosts
simultaneously. With one keystroke, such users can switch
between their jobs on these systems.

o LAT servers can balance user loads among hosts according to a
rating system that you set up.

o Users throughout the network can share LAT application
terminals. An LN03 printer on a LAT server, for example, is
not restricted to local host use.

Note that LAT software runs on host systems as well as on LAT servers.
This chapter discusses how to control LAT host software from a
DECSYSTEM-20. You can also issue commands directly to a LAT terminal
server. Refer to the documentation provided with your LAT terminal
server hardware for details on those commands.

13.2 LAT SOFTWARE
13.2 LAT SOFTWARE

Each host that supports the LAT protocol for interactive terminal
service periodically broadcasts this fact to all LAT terminal servers.
Each server maintains a list of hosts that have sent such messages. A
terminal user can issue a command to the server to display this list
to see which hosts are accessible.

_______
The logical path between a LAT host and server is called a LAT virtual
_______
circuit. There is one virtual circuit for each server/host pair that
has at least one active terminal session. When a terminal user
requests a connection to a host, the server creates a virtual circuit
to that host if none exists. Otherwise an already existing circuit is
used for data transmission. As system manager, you can decide the
maximum number of virtual circuits that can exist at a host. The

13-2
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

number that you decide upon can affect system performance. This topic
is discussed in Section 13.4.

Virtual circuit messages are transmitted between host and server at
_______ _____
periodic intervals determined by a circuit timer maintained in the LAT
server. When the timer expires, the server assembles into a single
virtual circuit message any terminal input received during the past
interval for a particular host and transmits it to the host. You can
set this timer only at the server. It has a recommended value of 80
milliseconds, which is the default.

The data associated with a particular terminal are grouped in a
_____
virtual circuit message in units called slots. A virtual circuit
message may contain slots from many terminals and may contain more
than one slot from a single terminal. The maximum size of a slot is
another parameter that you can set.

Having received a virtual circuit message, the host assembles as much
terminal output data as possible into a single message and transmits
it to the server. If no output is waiting for any terminal at that
server, a message is sent with no slots. The host's response message
acknowledges the previously received message from the server. This
message will be acknowledged by the server message transmitted at the
next tick of the circuit timer.

To reduce NI utilization and load on the host, the server transmits a
message only when there is something to send. It could happen that
when the server has no data to transmit, there is more terminal output
data waiting at the host. But because the last host message remains
unacknowledged, output flow from the host would stop. For this
reason, the host is permitted to transmit one "unsolicited" message to
the server. (Refer to the description of the HOST RETRANSMIT TIMER
dynamic parameter in Section 13.4 for additional information.) The
host sets a flag in the message, which forces the server to respond at
the next tick of the circuit timer. This "forced" response
acknowledges all the host's previously transmitted messages and
returns all transmit buffers so that they may be used again.

The host maintains a circuit timer with a default interval of 1
second. (You can set it up to 2 seconds.) The function of the host's
circuit timer differs from that of the server's circuit timer: it is
__________ _____
used solely as a retransmit timer. When the host sends an
"unsolicited" message, as described above, it starts its circuit
timer. Because the server's circuit timer is shorter than the host's,
the server should have acknowledged all outstanding host messages well
before the host's timer expires. If this does not happen, the host
retransmits all unacknowledged messages. This continues until either
the server responds with an acknowledgement, or the retransmit limit
is reached. If the retransmit limit is reached, the host assumes the
connection to the server is no longer useable and detaches all LAT
jobs from that server. (Refer to the description of the HOST
RETRANSMIT TIMER and the HOST RETRANSMIT LIMIT dynamic parameters in

13-3
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

Section 13.4.)

13.3 DECNET
13.3 DECNET

LAT, for the most part, is independent of DECnet. It does not require
DECnet for general operations. However, DECnet is required on at
least one host for start-up of LAT servers. Software from a host is
loaded into the server's memory by DECnet's Network Management. This
"down-line loading" of LAT servers occurs when the operator either
physically boots the server or triggers a boot of the server by
issuing a DECnet command from a host running DECnet. In either case,
any host that has DECnet and the appropriate load files may respond to
the boot, and then be selected by the server to load its memory.
DECnet is also needed for "dumping" files of LAT memory images to a
________________
host for problem diagnosis on the host. Refer to the DECnet-20/PSI-20
______ _________ _____
System Manager's Guide for the operator procedures involved in loading
and dumping LAT servers.

If a system supports DECnet, its node name and number are taken to be
the LAT name and number also. You do not need to respecify them in
the n-CONFIG.CMD file. Refer to the discussion of static parameters
in Section 13.4.

13.4 CONTROLLING LAT FROM THE HOST
13.4 CONTROLLING LAT FROM THE HOST

There are three ways for you or the operator or a system programmer to
control LAT from a host:

_________
o By rebuilding the monitor with new permanent parameters.

______
o By changing static parameters in the n-CONFIG.CMD file

_______
o By changing dynamic parameters with the LAT Control Program
subsystem of the OPR program

The lists below briefly describe these parameters. Many are discussed
more fully later.

Note that you can also control LAT from the server itself. Refer to
the documentation that came with your LAT server for details on server
commands.

_________ __________
Permanent Parameters

Normally, you do not need to change permanent parameters. To change
them, a system programmer familiar with monitor internals must rebuild
the monitor.

13-4
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

o FRAME SIZE - The host or server guarantees that it can
receive NI datagrams of at least this size. Usually three (
2 transmit and 1 receive) buffers of this size are used for
each LAT circuit. The default and recommended value is 1504
bytes.

o MAXIMUM HOST SERVICES - Sets the maximum number of services
that this host can offer. You can specify up to 254
services. The default and recommended maximum is 8. Refer
to Section 13.7, HOST SERVICES.

o MAXIMUM SLOTS - Sets the maximum number of slots that may be
entered into a virtual circuit datagram for a given circuit.
It is agreed upon by the server and host when the virtual
circuit between them is established. The default and
recommended value is 64.

o MAXIMUM SLOT SIZE - Sets the maximum number of bytes of data
(not including the slot header) that the host can accept from
the server in any slot. The slot size can range from 1 to
255. The default and recommended value is 40.

o MAXIMUM SERVER CACHE - Sets the maximum number of servers
whose characteristics are kept in memory. The LCP command,
SHOW SERVER, displays these characteristics. (Refer to
Section 13.8.3, Displaying Server Information.) The default
and recommended value is 20.

______ __________
Static Parameters

o DEFAULT LAT ACCESS STATE - Determines LAT accessibility to
and from the host. Values for the state are ON (the default)
and OFF. The LAT access state can be changed dynamically
with a LAT Control Program command. When the system is
reloaded, however, the value for this static parameter again
takes effect.

Refer to Section 13.5, STARTING AND STOPPING LAT, for
additional information.

o HOST NAME - Uniquely identifies the host within the local
area network. It may contain up to a combination of six
alphabetic and numeric characters, with at least one
alphabetic character. The default host name is the DECnet
node name, if the system supports DECnet. If the system does
not support DECnet, you must specify a name. For related
information, refer also to Section 13.7. That section
_______ _____
discusses host service names.

o HOST NUMBER - Uniquely identifies the host within the local
area network. The number can range from 0 to 65535. It is

13-5
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

passed to the server when the virtual circuit between host
and server is established. The default number is the DECnet
node number, if the system supports DECnet. This is an
optional parameter for use by one of your system programmers.

The n-CONFIG.CMD file commands that set these static parameters are:

- NODE hostname hostnumber

- LAT-STATE default LAT access state

where the default LAT access state is ON or OFF

_________ ______ ______ _________ _____
| Refer to the DECnet-20 PSI-20 System Manager's Guide for
| DECnet-related SETSPD commands, if applicable.

_______ __________
Dynamic Parameters

As system manager, you will probably be most concerned with dynamic
parameters:

o HOST GROUP CODES - Defines the group codes for the host.
They can range from 0 to 255. Code 0 is enabled by default.
You can define any number of codes for a host. A LAT server
will not connect to the host unless both server and host have
at least one group code defined in common. Refer to Section
13.6, LAT GROUPS.

o HOST IDENTIFICATION - Supplies information about the host.
It appears in various displays requested by managers and
users. The identification may contain up to 64 printable
characters. The default identification is the TOPS-20 banner
message from SYSTEM:MONNAM.TXT.

o HOST NUMBER - Uniquely identifies the host within the local
area network. The number can range from 0 to 65535. It is
passed to the server when the virtual circuit between host
and server is established. The default number is the DECnet
node number if the system supports DECnet. This is an
optional parameter for use by one of your system programmers.

o HOST MULTICAST TIMER - Determines the interval at which the
host announces to all servers that its LAT terminal service
is available. The default value is 60 seconds.

o HOST RETRANSMIT LIMIT - Sets the maximum number of times that
the host retransmits a message at the expiration of HOST
CIRCUIT TIMER. The virtual circuit is closed and all jobs
associated with the virtual circuit become detached when this
limit is exceeded. The default value is 30 times.

13-6
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

o HOST RETRANSMIT TIMER - Determines the interval at which the
host retransmits any unacknowledged messages to the server.
It is started when the host sends an "unsolicited" message
and is stopped when the host receives any message from the
server that acknowledges all outstanding messages. The
default value is 1000 milliseconds (one second). It can be
set from 1000 to 2000 milliseconds, however. Refer to the
description of the HOST RETRANSMIT LIMIT parameter for
related information.

o HOST SERVICE NAME - Specifies the name of a service that the
host provides for users. It may contain a combination of up
to 16 alphabetic and numeric characters as well as the dollar
sign ($),dash (-), and underscore (_). The default service
name is the host name. Refer to Section 13.7, HOST SERVICES.

o HOST SERVICE NAME RATING - Assigns a rating to a service
name. It can be a fixed number in the range of 0 to 255 or
it can be DYNAMIC. Refer to Section 13.7.1, Service Ratings.

o LAT ACCESS STATE - Determines LAT accessibility to and from
______
the host. The default state allows LAT access. This dynamic
parameter is affected by the LCP START and STOP commands.

o MAXIMUM ACTIVE CIRCUITS - Sets the maximum number of LAT
virtual circuits that can exist simultaneously at the host.
The default value is 20.

o MAXIMUM SESSIONS - Sets the maximum number of terminal
sessions that may be active at the host simultaneously. The
default value is equivalent to the number of terminals
allowed in your system configuration. Section 13.1 discusses
sessions.

The dynamic parameters are changed with the LAT Control Program (LCP).
To use LCP, the operator enters the following from the OPR prompt:

1. For many LCP commands:

_____ ________
OPR> ENTER LCP
____ _____________
LCP>
____ _____________
LCP>
____ _____________
LCP>
____ _____________
LCP>
___________
LCP> RETURN
OPR>

2. For a single command:

___ ____ _____________
OPR> LCP
OPR>

13-7
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

The LCP commands also let you start and stop operations, check
parameter values and other information, and access counters maintained
by the NI and servers. These LCP functions are discussed in later
__________ _______ ________ _________ ______
sections. The Operator's Command Language Reference Manual fully
describes LCP.

The following is a summary of the LCP commands:

START
STOP
SET GROUPS (0,1-5,....255)
SET SERVICE-NAME service-name{/RATING:{nn|DYNAMIC}|
/IDENTIFICATION:"text"|
nothing}
SET IDENTIFICATION "text"
SET NUMBER number
SET MAXIMUM ACTIVE-CIRCUITS number
SET MAXIMUM SESSIONS number
SET MULTICAST-TIMER seconds
SET RETRANSMIT LIMIT number
SET RETRANSMIT TIMER number

CLEAR GROUPS (0,1-5,....255)
CLEAR SERVICE-NAME service-name
CLEAR IDENTIFICATION
CLEAR MAXIMUM CIRCUITS
CLEAR MAXIMUM SESSIONS
CLEAR MULTICAST-TIMER
CLEAR NUMBER
CLEAR RETRANSMIT LIMIT
CLEAR RETRANSMIT TIMER

SHOW CHARACTERISTICS
SHOW HOST-INITIATED-REQUESTS
SHOW PENDING-REQUESTS
SHOW SESSIONS
SHOW COUNTERS{/SERVER:server-name|
nothing}
SHOW SERVER{/ALL|
server-name|
nothing}

ZERO COUNTERS{/SERVER:server-name|
nothing}

13.5 STARTING AND STOPPING LAT
13.5 STARTING AND STOPPING LAT

Support for LAT servers is enabled by default in TOPS-20. That is,the
LAT access state is enabled unless specifically disabled in the
n-CONFIG.CMD file. Disabling it is useful if you wish to establish

13-8
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

guidelines and set restrictions for LAT use before you enable it. You
can set groups and the host identification, for example, before
enabling LAT. The operator can enable and disable the LAT access
state dynamically with the LCP START and STOP commands.

The host name and number are other parameters that you specify in the
n-CONFIG.CMD file (unless DECnet is supported on the host). They are
required items that uniquely identify the host in the local area
network.

After the host name and number have been established, and the LAT
access state has been enabled, the operator starts LAT by booting the
server or by issuing a DECnet command from the host, as discussed in
Section 13.3.

It is recommended that you disable the LAT access state if LAT is not
intended to be used for an extended period of time. This will improve
system performance.

13.6 LAT GROUPS
13.6 LAT GROUPS

_____ _____
By using group codes, you can divide the local area network into
smaller networks. That is, you can allow or prevent connections
between specified servers and hosts. When users give a LAT command to
display the names of available services, only those services
corresponding to hosts within a server's "group" are displayed.
(Refer to Section 13.7 for a discussion of services.) Codes in the
range of 0 to 255 can be assigned to DECSYSTEM-20s and LAT servers. A
LAT server will connect to a host only if it has at least one group
code defined in common with the host. (Refer to the LAT documentation
set for information on assigning codes to LAT servers.) Note that code
0, the default for hosts and servers, allows universal access. When
servers and hosts implement the default, users have access to all
hosts.

In the example below, an operator enables access between this
DECSYSTEM-20 and any LAT server assigned a code in the range of 1 to
5. No connection is allowed with any other server.

___ ______ ________
LCP> SET GROUPS 1:5
_____ ______ ______
LCP> CLEAR GROUPS 0

User terminals wired to servers in any one of these groups will be
able to access the system.

Group settings stay in effect until reset with the CLEAR GROUPS
command.

13-9
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

13.7 HOST SERVICES
13.7 HOST SERVICES

_______ ____
Another name for a LAT host is a service node (a node being a system
in a network). This refers to the fact that hosts provide computing
________
services. Users access hosts in order to have some type of computing
need served--to compile a program, update a file, or print a report,
_______
for example. LAT terminal servers deliver these services to users.

Users refer to hosts by the services that they offer, rather than by
host name. When they request the LAT server to connect them to a
host, they specify a service name that you have previously established
for that host. The server maintains a list of host and service names
and lets users display service names assigned to hosts in the user's
group. (The server also displays any service identification text you
specified.) With the SET SERVICE-NAME command, you can specify one or
more services for a host:

___ ____________ ___________________________________ ____________
LCP> SET SERVICE-NAME LASER-PRINTER/IDENTIFICATION:"OMEGA System"
___ ____________ _________________
LCP> SET SERVICE-NAME ARPA-GATEWAY

The default service name for a host is the host name. You may want to
specify some identifying text for such services. For example, on the
host ALPHA, you could give the command:

___ ____________ _______________________ ______ ____________
LCP> SET SERVICE-NAME ALPHA/IDENTIFICATION:"A DECnet System"

You can assign the same service name to multiple hosts. The following
section discusses this topic.

13.7.1 Service Ratings
13.7.1 Service Ratings

You can arrange for LAT servers to distribute users among host
systems, according to a rating system that you set up. This is useful
for hosts with service names in common. Perhaps several systems are
part of a CFS cluster. You can assign the same service name, CFS, on
_______ ______
each host but specify a unique service rating for each one:

___ ____________ ____________
LCP> SET SERVICE-NAME CFS/RATING:3
________________ _________________ _____________
/IDENTIFICATION: "ALPHA/BETA/OMEGA Cluster"
___ ____________ ____________
LCP> SET SERVICE-NAME CFS/RATING:9
________________ _________________ _____________
/IDENTIFICATION: "ALPHA/BETA/OMEGA Cluster"

If a user requests connection to CFS, the server will pick the host
with the highest rating for that service. If, for some reason, that
connection fails, the server will try the host with the next highest
rating.

13-10
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

Ratings can be a fixed number from 0 to 255. Or they can be DYNAMIC.
When hosts with common service names have DYNAMIC ratings for the
service, the hosts compute ratings using an algorithm based on system
load averages. Generally, the host with the lowest load average is
given the highest rating. That host probably has the greatest
available computing capacity.

You can use common service names for any collection of hosts offering
the same function.

The default rating is 1 for the default service name, and 0 for
services created with the SET SERVICE-NAME command.

_______ ______ _______
Service Rating Example

Hosts SOLAR and LUNAR, in addition to providing a timesharing service
as service names SOLAR and LUNAR, each have the service name CFS.
SOLAR assigns a host rating to name CFS of 5; whereas LUNAR assigns 3.
A LAT terminal user, when displaying the list of available LAT
services, will see SOLAR, LUNAR, and CFS. If the user connects to
CFS, the server will first attempt to access SOLAR. If that fails, it
will try LUNAR.

13.8 MONITORING LAT FROM THE HOST
13.8 MONITORING LAT FROM THE HOST

The following sections show various LAT informational displays.

13.8.1 Displaying User Information
13.8.1 Displaying User Information

The SHOW SESSIONS command displays information about connected LAT
terminals:

____ _____________
LCP>SHOW SESSIONS
LCP>
10:52:26 [LCP] Active LAT sessions

Job Line Program Server Name Port Name User
105 326 EXEC COTTAGE PORT7 DOPEY
114 327 LPRINT PALACE *LASER-PRINTER THE_QUEEN
114 330 LPRINT PALACE ROYAL-TTY THE_QUEEN
120 331 EXEC COTTAGE PORT3 GRUMPY
113 332 EMACS PALACE KINGS-TTY THE_KING
* indicates an Application Terminal

The TOPS-20 SYSTAT user command shows much of this same information.

13-11
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

13.8.2 Displaying Host Parameters
13.8.2 Displaying Host Parameters

The SHOW CHARACTERISTICS command displays many of the LAT parameter
settings:

____ ____________________
LCP>SHOW CHARACTERISTICS

LCP>
09:20:41 [LCP] -- Host Characteristics --

LAT Access State: ON
Host Name: ALPHA
Host id: ALPHA, TOPS-20 Development System, TOPS-20 Monitor 7(20753)
Host number: 140
Retransmit Limit: 60
Retransmit Timer: 1000
Multicast Timer: 30
Groups: 3:4,7,10,18,21:23,45,47

Current Maximum
------- -------
Allocated circuits 6 32
Active circuits 6 20
Sessions 8 128

Service name Rating Identification
------------ ------ ------------------------
ALPHA 1 ALPHA - More Networks per CPU
SGROUP D Software Engineering Cluster

The D that appears for the service name rating indicates a dynamic
rating.

13.8.3 Displaying Server Information
13.8.3 Displaying Server Information

The SHOW SERVER command displays information about servers with
connections to this host. The host tries to keep information in
memory on all servers that have connected since the last monitor load.
However, this could require a very large data base. Therefore,
information is kept only for the number of servers specified in the
MAXIMUM SERVER CACHE permanent parameter. (Refer to Section 13.4 for
information on this parameter.) When this number is exceeded, the
oldest inactive entry is deleted from the data base, making room for a
new entry.

13-12
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

You can specify a single-line summary for each server or a detailed
display for a single server:

____ _______________
LCP>SHOW SERVER/ALL
LCP>
14:55:32 [LCP] Summary of all servers

Server Name(Number): Finance(8) Address: 08-00-2B-00-17-BA
Server Name(Number): Accounting(22) Address: 08-00-2B-02-08-C0
Server Name(Number): Payroll [LAT3](3) Address: AA-00-03-01-25-38
Server Name(Number): Development(2) Address: AA-00-03-01-06-AB

____ ______ ____________
LCP>SHOW SERVER FINANCE
LCP>
14:56:12 [LCP] Information about server Finance

Server Number: 8
Server Location: Near vending machines
Server Type: DECserver-100
Ethernet Address: 08-00-2B-00-17-BA
Server Status: Connected
Max Slots: 32
Data Link Size: 1518
Circuit Timer(ms): 80
Keep-alive Timer(s): 20

13.8.4 Displaying LAT Counters
13.8.4 Displaying LAT Counters

The SHOW COUNTERS command displays counters kept by LAT software
modules. These counters provide information such as the number of
messages transmitted, the number of transmission errors, and so on.
You can obtain these numbers for a single server, or you can obtain
cumulative figures for all servers that have connected since the last
monitor reload:

____ _____________
LCP>SHOW COUNTERS
LCP>
14:48:11 [LCP] Counter totals for all servers

Messages received: 33955
Messages transmitted: 36413
Messages retransmitted: 0
Sequence errors received: 21
Illegal messages received: 0
Illegal slots received: 0
Resource failures: 0

13-13
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

____ _________________________________
LCP>SHOW COUNTERS/SERVER:PUBLICATIONS
LCP>
14:48:34 [LCP] Counters for server PUBLICATIONS

Messages received: 28189
Messages transmitted: 30132
Messages retransmitted: 0
Sequence errors received: 0
Illegal messages received: 0
Illegal slots received: 0
Resource failures: 0

The single-server counts are available even after a server has
disconnected from the host. However, this availability, as the
information displayed with the SHOW SERVER command, depends on the
limit set with the MAXIMUM SERVER CACHE permanent parameter.

The cumulative counters are incremented each time individual server
counters are. It is possible that the sum of all server counters is
not equal to the cumulative counts, because you can zero the counters
for any server, as discussed below, or the data base may have been
cleared according to the MAXIMUM SERVER CACHE parameter limitation.

When using the counters to monitor performance or to isolate hardware
failures, it is often desirable to be able to reset (or zero) the
counters. The ZERO COUNTERS command lets you do this. You can reset
counters for one server or for all the servers. Resetting the
cumulative counts does not affect the counts of the individual
servers.

13.8.5 Displaying Pending Requests for LAT Application Terminals
13.8.5 Displaying Pending Requests for LAT Application Terminals

The SHOW PENDING-REQUESTS command displays information on pending,
rejected, and canceled requests for LAT application terminals:

____ _____________________
LCP>SHOW PENDING-REQUESTS
LCP>
09:20:49 [LCP] -- Current Pending Connect Requests --

Job Status Server Name Service Name Port Name User
--- ------ ---------------- ---------------- ------------ ----------
146 QUE 1 LAT100 LN03 WADDINGTON

QUE nn means request was queued; entry is nn requests into the queue

A total of 1 request was found
LCP>

13-14
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

13.8.6 Displaying All Print Requests for LAT Application Terminals
13.8.6 Displaying All Print Requests for LAT Application Terminals

The SHOW HOST-INITIATED-REQUESTS command displays information on all
active and pending requests for LAT application terminals:

LCP>SHO HOST
LCP>
09:21:10 [LCP] -- Current Host-Initiated Requests --

Job Status Server Name Service Name Port Name User
--- ------ ---------------- ---------------- ---------------- ---------------
130 TTY334 LAT100 LN03 OPERATOR
146 QUE 1 LAT100 LN03 WADDINGTON

TTYnnn means connect is active and terminal nnn was assigned
QUE nn means request was queued; entry is nn requests into the queue

A total of 2 requests were found
LCP>

13-15
LAT TERMINAL SERVERS
LAT TERMINAL SERVERS

INDEX

-A-
-A- Application terminal, 13-2
Automatic Volume Recognition
ABSOLUTE-INTERNET-SOCKETS (AVR), 8-15, 8-17
capability, 5-39 AVR, 8-15, 8-17
Access control job (ACJ), 11-1
-B-
class scheduler, 10-14 -B-
Accounts
account data file commands, B362LB.REL, 3-7
6-13 Backup
ACTGEN program, 6-17 common policy, 7-4
creating, 6-1 console front end files, 7-10
creating the data base, 6-7 full dumps, 7-2
disabling, 6-2 system, 7-1
enabling, 6-2 system crash tape, 7-6, 7-8
errors, 6-19 tape requirements, 7-4
OPERATOR account, 6-19 BASIC.EXE, 3-7
selecting schemes, 6-3 Batch jobs
setting up for shift changes, scheduling low priority to,
6-3 10-15
setting up with existing files, Batch system
6-2 tailoring, 3-29
validating, 6-19 BATCON.EXE, 3-7
ACCOUNTS-TABLE.BIN, 3-4 Beware file, 1-1
, 3-18 Bias controls, 10-15
ACJ, 11-2 Blocking factor
ACJDEC program, 11-3 magnetic tape, 7-6
DISABLE command, 11-14 Boot Structure, 4-2
ENABLE/DISABLE command, 11-3, BS:, 12-17
11-5 BUGCHK, 9-14
ENABLE/DISABLE command BUGINF, 9-14
qualifiers, 11-14 BUGS.MAC, 3-4
HELP command, 11-3 BUILD.MEM, 4-20
log files, 11-21
-C-
SAVE command, 11-19 -C-
SET command, 11-17
SHOW command, 11-18 Cache
starting, 11-2 program name, 10-17
TAKE command, 11-3 Capabilities, 5-38
USER command, 11-15 CDRIVE.EXE, 3-7
WRITE command, 11-19 CFS, 12-1
ACTGEN program, 6-17 ALLOW command, 12-5
ACTGEN.EXE, 3-7 batch jobs and, 12-8, 12-13
ACTGEN.HLP, 3-7 CFRECN BUGHLT, 12-20, 12-21
ACTSYM.UNV, 3-7 "cluster data gathering"
AN-MONBIG.EXE, 3-4 (CLUDGR), 12-9
AN-MONDCN.EXE, 3-4 cluster GALAXY, 12-9
AN-MONMAX.EXE, 3-4 date/time, 12-6
ANAUNV.UNV, 3-7 DECnet and, 12-7

Index-1

CFS (Cont.) Cluster GALAXY, 3-31, 12-9
directory groups, 12-14 Cluster printers, 3-30
dismounting structures, 12-19, CMD.REL, 3-8
12-24 CMD.UNV, 3-8
DMP:, 3-23 COBDDT.HLP, 3-8
dual-ported disks, 12-5, 12-21, COBDDT.REL, 3-8
12-24 COBOL.EXE, 3-8
DUMPER, 12-20 COBOL.HLP, 3-8
^ECEASE, 12-24 COMAND.CMD, 3-4
ENQ-DEQ, 12-8 Common File System
errors, 12-21 see CFS
exclusive structures, 12-18 Computer room security, 2-1
file server, 12-4 CONFIDENTIAL
hardware, 12-2 capability, 5-39
IPCF, 12-8 CONFIG.CMD, 2-4, 3-3
limitations, 12-8 Console front-end files, 3-25,
load balancing, 12-8, 12-13 4-2, 7-10
logical names, 12-15 CREF.EXE, 3-8
login structure, 12-16 CREF.HLP, 3-8
mail files, 12-11
-D-
massbus disks, 12-4, 12-24 -D-
MSCP file server, 12-4, 12-11,
12-24 DECnet, 9-17, 12-7
printers, 3-30 Cluster GALAXY, 12-10
privileged users, 12-16 DQS printers, 3-30
served disks, 12-5, 12-11, DECNET-ACCESS
12-20, 12-21, 12-24 capability, 5-39
sharing structures, 12-15 DEFAULT-EXEC:, 3-23
software, 12-6 Device names, 4-10
structure names, 12-15 DEVICE-STATUS.BIN, 3-4
system structure, 12-3, 12-18 Diagnostic link
tape drives, 8-20 remote (KLINIK), 9-11
tightly-coupled systems and, DIL.LIB, 3-8
12-8 DIL.REL, 3-8
updating files, 12-11 DILV7.FOR, 3-8
user groups, 12-14 Directories
usernames, 12-14 creating, 5-1
users, 12-7 creating (central control), 5-2,
writing files, 12-11 5-4
CHECKD program, 4-13 creating (project and central
login structure, 12-16 control), 5-3, 5-22
CHECKD.EXE, 3-4, 3-8 creating (project control), 5-2,
CHECKD.HLP, 3-8 5-14
CHKPNT.EXE, 3-8 printing information about,
CHKPNT.HLP, 3-8 5-40
CI protection code, 5-7, 5-26
making unavailable (non-CFS), restoring, 9-2
9-12 system, 3-1
CI (CFS), 12-3 Directory group numbers, 5-29
CI20, 12-4 Disk drives, 4-12
Class scheduler, 10-2 dual ported, 4-17
CLUDGR, 12-9 dual-ported (CFS), 12-21, 12-24

Index-2

Disk drives (Cont.) FE.EXE, 3-9
dynamic dual porting, 10-19 FE.HLP, 3-9
timeout interval, 9-13 FEDDT.EXE, 3-5, 3-9
unavailable, 9-12 FILCOM.EXE, 3-9
Disk packs FILCOM.HLP, 3-9
reinitializing, 10-18 FILDDT.EXE, 3-9
Disk space File archiving, 8-1, 8-2
allocating, 5-23 archive cycle, 8-3
determining, 4-21 recycling tapes, 8-3, 8-11
enforcing quotas, 5-24 retrieving files, 8-5, 8-7
permanent quota, 5-23 sample procedure, 8-5
working quota, 5-23 setting up system, 8-3
DITV7.FOR, 3-8 when to create tapes, 8-5
DIXV7.FOR, 3-8 File Descriptor Block (FDB), 8-4
DLUSER program, 9-10 File migration, 8-2, 8-7
DLUSER.EXE, 3-8 processing retrieval requests,
DLUSER.HLP, 3-8 8-11
DMP:, 3-23, 9-15 recycling tapes, 8-11
Documents setting up system, 8-8
available from DIGITAL, 1-1 using DUMPER, 8-10
prepared at your site, 1-2 using REAPER, 8-8
Domestic structures, 4-16 File system
DQS printers, 3-30 restoring, 9-9
DUMP-ON-BUGCHK, 9-14 Files
DUMP.CPY, 3-4 protection code, 5-26
DUMP.EXE, 3-4 FORDDT.HLP, 3-9
0DUMP11.BIN, 3-3 FORDDT.REL, 3-9
DUMPER program, 7-1 Foreign structures, 4-16
CFS systems, 12-20 FORMAT.EXE, 3-9
file archiving, 8-3 FORMAT.HLP, 3-9
file migration, 8-10 FOROTS.EXE, 3-9
password encryption, 11-26 FORTRA.EXE, 3-9
DUMPER.EXE, 3-9 Front-end files, 3-25, 4-2, 7-10
DUMPER.HLP, 3-9
-G-
DX20LD.EXE, 3-9 -G-
DXMCA.ADX, 3-9
GALAXY documentation file, 3-31,
-E-
-E- 3-34
GALCNF, 3-9
^ECEASE, 12-24 GALGEN.EXE, 3-9
EDDT.REL, 3-9 GLOBS.UNV, 3-10
EDIT.EXE, 3-9 GLXLIB.EXE, 3-10
EDIT.HLP, 3-9 Groups, 5-7
ENQ-DEQ directory, 5-29
capability, 5-39 user, 5-29
ERRMES.BIN, 3-4
-H-
EXEC.EXE, 3-4 -H-

-F-
-F- HELP.HLP, 3-10
, 3-20
FAL.EXE, 3-13 HLP:, 3-22
FDB, 8-4 Home block, 4-4

Index-3

HOSTS.TXT, 3-5 LAT (Cont.)
service ratings, 13-10
-I-
-I- services, 13-5, 13-7, 13-10
sessions, 13-2, 13-7
IBMSPL.EXE, 3-10 slots, 13-3, 13-5
INFO.EXE, 3-10 starting and stopping service,
INTERNET-ACCESS 13-5, 13-7, 13-8
capability, 5-39 users, 13-2, 13-11
INTERNET-WIZARD virtual circuit, 13-2, 13-6,
capability, 5-39 13-7
INTERNET.ADDRESS, 3-5 LCPORN.REL, 3-10
INTERNET.GATEWAYS, 3-5 LCPTAB.REL, 3-10
INTERNET.NAMESERVERS, 3-5 LIBARY.EXE, 3-10
IPALOD.EXE, 3-5 LIBARY.HLP, 3-10
IPCF LIBO12.EXE, 3-10
capability, 5-39, 12-8 LIBOL.REL, 3-10
ISAM.EXE, 3-10 LINK.EXE, 3-10
ISAM.HLP, 3-10 LINK.HLP, 3-10
LISSPL.EXE, 3-10
-J-
-J- Local Area Network, 13-1
Local Area Transport
Jobs See LAT, 13-1
hung, 9-12 Logical names, 3-20
CFS, 12-15
-K-
-K- LOGIN command, 6-19
dates/times of login, 11-30
KDDT.REL, 3-10 fast login, 11-31
KLINIK, 9-11 Login structure, 4-2, 12-16
KNILDR.EXE, 3-5, 3-10 LOGIN.CMD, 3-5
LOGOUT.CMD, 3-5
-L-
-L- LP64.RAM, 3-10
LP96.RAM, 3-11
Labeled tapes, 8-13 LPTSPL.EXE, 3-11
LAT, 13-1 LPTUSR.MAC, 3-31, 3-34
circuit timer, 13-3
-M-
counters, 13-13 -M-
DECnet and, 13-4
DUMP-ON-BUGCHK, 9-17 MACREL.REL, 3-11
features, 13-2 MACRO.EXE, 3-11
groups, 13-6, 13-9 MACRO.HLP, 3-11
host identification, 13-6 MACSYM.UNV, 3-11
host name, 13-5 Magnetic tape, 8-1
host number, 13-5 backup requirements, 7-5
LCP commands, 13-7 blocking factor, 7-6
load balancing, 13-10 recycling, 8-11
multicast timer, 13-6 Mail, 3-24, 12-11
parameters, 13-4, 13-12 MAINTENANCE
printers, 3-30 capability, 5-39
retransmit limit, 13-6 MAKDMP.EXE, 3-11
retransmit timer, 13-3, 13-7 MAKLIB.EXE, 3-11
server characteristics, 13-5, MAKLIB.HLP, 3-11
13-12 MAKRAM.EXE, 3-11

Index-4

MAKRAM.HLP, 3-11 Operator (Cont.)
MAKVFU.EXE, 3-11 shared disk drive procedure,
MAKVFU.HLP, 3-11 4-18
MAPPER.EXE, 3-11 shared tape drive procedure,
MDDT.REL, 3-11 8-18
2060-MONBIG.EXE, 3-3 Operator shift change log, 1-9
MONITR.EXE, 3-5 Operator work request form, 1-9
2060-MONMAX.EXE, 3-3 , 3-18
MONNAM.TXT, 3-5 OPR, 9-15
MONSYM.REL, 3-12 OPR.EXE, 3-12
MONSYM.UNV, 3-12 OPR.HLP, 3-12
Mountable structure sign-up log, ORION.EXE, 3-12
1-6 OVRLAY.REL, 3-12
Mountable structures, 4-5, 9-10
-P-
MOUNTR.EXE, 3-12 -P-
MS.EXE, 3-11
MS.HLP, 3-11 PA1050.EXE, 3-12
MSCPAR.UNV, 3-12 Page, 4-19
Password encryption, 11-23
-N-
-N- algorithms, 11-25
DUMPER program, 11-26
NEBULA.EXE, 3-12 multiple-system environment,
Network Interconnect 11-25
See NI, 13-1 Password management, 5-7, 11-28
, 3-17 PAT.EXE, 3-12
, 3-17 Performance, 10-1
NEW:, 3-21 batch background, 10-15
, 3-19 bias controls, 10-15
NFT.EXE, 3-12 class scheduler, 10-2
NFT.HLP, 3-12 dynamic dual porting, 10-19
NI, 13-1 interactive versus
setting unavailable, 9-12 compute-bound programs,
NMLT20, 3-12 10-15
NORMAL.VFU, 3-12 program name cache, 10-17
NRT, 3-24 reinitializing disk packs,
10-18
Permanent storage, 5-23
-O-
-O- PHYPAR.UNV, 3-12
PLEASE.EXE, 3-12
Offline structures, 9-12 POBOX:, 3-24, 12-11
OLD:, 3-22 Power failures, 9-11
, 3-19 Printers
OPERATOR remote, 3-30
capability, 5-39 terminal, 3-34
Operator Privileges, 5-38, 12-16
accounting, 6-19 Program name cache, 10-17
alternative to PLEASE requests, PROGRAM-NAME-CACHE.TXT, 3-5
3-20 PROLOG.UNV, 3-12
archiving procedures, 8-5 PS:, 12-17
handling user requests, 2-1 PTYCON.ATO, 3-3
, 3-20 PTYCON.EXE, 3-12
scheduling tasks, 2-2 PTYCON.HLP, 3-13

Index-5

-Q-
-Q- Security, 5-7, 11-1
access control job, 11-1
QUASAR.EXE, 3-13 computer room, 2-1
fast login, 11-31
-R-
-R- labeled tapes, 8-16
last login information, 11-30
RA60, 4-13, 7-5 password encryption, 11-23
RA81, 4-13, 7-5 password management, 11-28
RDMAIL.EXE, 3-13 passwords vs groups, 5-7
RDMAIL.HLP, 3-13 SELOTS.EXE, 3-14
REAPER program, 8-8 SEMI-OPERATOR
REAPER.CMD, 3-5 capability, 5-39
REAPER.EXE, 3-13 SERCOD.UNV, 3-14
REAPER.HLP, 3-13 SERR:, 3-22
Reinitializing disk packs, 10-18 SETSPD, 2-4
, 3-20 SETSPD.EXE, 3-3
Remote printers, 3-30 Shift change log, 1-9
characteristics, 3-33 SIX12.REL, 3-14
printer definitions, 3-32 Software
REMOTE-PRINTING.CMD file, 3-32 after installation, 3-1
RERUN.EXE, 3-13 before installation, 2-1
RERUN.HLP, 3-13 checking (UETP), 3-29
RETRFB.SPE, 3-13 updating, 2-4, 3-17, 3-19
RFB.EYE, 3-13 SORT.EXE, 3-14
RMS.EXE, 3-13 SORT.HLP, 3-14
RMSCOB.EXE, 3-13 SPEAR.EXE, 3-14
RMSINI.REL, 3-13 SPOOL:, 3-25
RMSINT.R36, 3-13 , 3-18
RMSINT.UNV, 3-13 SPRINT.EXE, 3-14
RMSUTL.EXE, 3-13 SPROUT.EXE, 3-14
SPRRET.EXE, 3-14
definition, 3-2 SPRSUM.EXE, 3-14
rebuilding on system structure, Star coupler, 12-3
9-5 Structures
restoring, 9-3 alias, 4-11
RP06, 4-13, 7-5 boot, 4-2
RP07, 4-13, 7-5 BS:, 12-17
RP20, 4-13, 7-5 differences between system and
RSX20F, 3-25 mountable, 4-6
DUMP-ON-BUGCHK, 9-17 dismounting, 4-15
RSX20F.MAP, 3-6 dismounting (CFS), 12-19
RSXFMT.EXE, 3-13 domestic, 4-16
RSXFMT.HLP, 3-13 dumpable, 9-15
RUNOFF.EXE, 3-13 exclusive (CFS), 12-18
RUNOFF.HLP, 3-14 foreign, 4-16
increasing the size of, 4-13
login, 4-2, 12-16
-S-
-S- mountable, 4-5, 4-7, 4-8
re-creating, 9-10
SCAPAR.UNV, 3-14 multiple, 4-7
SDDT.EXE, 3-14 names, 4-9, 4-11
Secure files, 11-4, 11-32 names (CFS), 12-15

Index-6

Structures (Cont.) TCX.EXE, 3-14
offline, 9-12 TCX.HLP, 3-14
PS:, 12-17 Terminal printers, 3-34
public, 4-2 Terminal server
sharing among CFS systems, definition, 13-1
12-15 /TERMINAL-CHARACTERISTIC: switch,
sharing between systems, 4-17 3-31, 3-34
size, 4-11 TERMINAL.HLP, 3-14
system, 4-2 TGHA.EXE, 3-6
system limit, 4-8 TGHA.HLP, 3-6
Structures > similarities between Timeout problems, 9-17
system and mountable, 4-6 TOC.EXE, 3-14
TOC.HLP, 3-14
files, 3-7 TOPS-20.DOC, 3-6
restoring, 3-16 Tuning mechanisms, 10-1
Supplies, 2-2 TV.EXE, 3-14
Swapping space, 4-19
-U-
SYS:, 3-21 -U-
SYSJOB.EXE, 3-3
SYSJOB.HLP, 3-6, 3-14 UDDT.EXE, 3-15
SYSJOB.RUN, 3-4 UETP, 3-29
SYSTAP.CTL, 3-14 ULIST program, 5-40
System ULIST.EXE, 3-15
problems, 9-1 ULIST.HLP, 3-15
selecting features, 2-4 User requests, 1-9, 2-1
System access request form, 1-6 User-group numbers, 5-29
System crash tape, 7-6, 7-8 Usernames
System log, 1-3 assigning, 5-4, 5-8, 5-15, 5-22
System structure CFS, 12-14
backup, 4-14
-V-
contents, 4-3 -V-
definition, 4-2
dual porting, 12-5 VERIFY.EXE, 3-15
re-creating, 7-6, 7-8 VOLID, 8-14
rebuilding ,
-W-
9-5 -W-
, 3-18
SYSTEM.CMD, 3-6 WATCH.EXE, 3-15
SYSTEM:, 3-21 WATCH.HLP, 3-15
WHEEL
files, 3-3 capability, 5-39
restoring, 3-6 Windfall, 10-4
Work request form, 1-9
-T-
-T- Working storage, 5-23

Tape drive allocation, 8-2, 8-12
-X-
Tape drives -X-
sharing between systems, 8-18
Tape labeling, 8-13 XPORT.REL, 3-15
TAPNAM.TXT, 3-6 XRMS.EXE, 3-15