HP OpenVMS Systems Documentation

If each user has a unique UIC, you can use the Backup utility (BACKUP) to remove the user's files, even if the files are scattered throughout the directory structure. See the Backup utility section in the OpenVMS System Management Utilities Reference Manual for more information.

Examples

1. The following example of a BACKUP command is used to remove files:

   $ BACKUP/DELETE PUBLIC:[...]/BY_OWNER=[21,103] MTA0:PUBLICUIC.SAV

   
   This BACKUP command copies and deletes only those files owned by the specified UIC on disk PUBLIC. The files are copied into a save set named PUBLICUIC.SAV on device MTA0. Note that the BACKUP/DELETE command does not delete the directory files (file type .DIR) for the account.
2. To recover lost files, enter the ANALYZE/DISK_STRUCTURE command in the following format:

   ANALYZE/DISK_STRUCTURE/REPAIR/CONFIRM device-name:

   
   See Section 9.12.3 for a complete description of how to recover lost files. See the OpenVMS System Management Utilities Reference Manual for information on using the Analyze/Disk_Structure utility.

To disable an account without deleting it, set the disable user flag (/FLAGS=DISUSER) using AUTHORIZE. If the user is logged in, the account is disabled only after the user logs out.

7.8 Restricting the Use of Accounts

Workload schedules often dictate the days and times your system is used to perform specific operations. Depending on the nature of the work performed at your site, you might want to control when certain users are allowed to log in. Use the Authorize utility (AUTHORIZE) to place controls in the login characteristics fields of the UAF record to restrict the days and times a user can log in and to inhibit certain login functions.

The following sections describe how to perform these tasks:

For a detailed description of the qualifiers used to restrict the use of accounts, see the Authorize utility section in the OpenVMS System Management Utilities Reference Manual.

7.8.1 Setting Day Types

You can restrict the use of certain accounts by defining the days of the week as either PRIMARY or SECONDARY, and then assigning login restrictions to these day types. For example, if you define the days Saturday and Sunday as SECONDARY days, then any restrictions you assign to the SECONDARY day type apply to both.

You can assign two types of login restrictions to either day type:

The default user record defines the five weekdays (Monday through Friday) as PRIMARY days, and the two weekend days (Saturday and Sunday) as SECONDARY days.

The way you define days and assign restrictions depends on your site. For example, suppose that on weekdays your system supports a large number of interactive users, but on weekends it is used for certain operations that require dedicated system resources. By assigning restrictions to the SECONDARY day type, you can restrict users from accessing the system during the days defined as SECONDARY. You can change these day type definitions for any account using the following AUTHORIZE qualifier:

/PRIMEDAYS=([NO]day[,...])

The /PRIMEDAYS qualifier uses a list of day names to define the PRIMARY and SECONDARY days of the week. To define a day as a SECONDARY day, use the prefix NO before the day name. Any days you omit from the list take their default value.

7.8.2 Restricting Logins to Specific Times

By default, there are no restrictions on login hours. You can specify login time restrictions using the following AUTHORIZE qualifiers:

Interactive users still logged in when the access time has expired receive the following warning message and have 2 minutes to log out before their processes are terminated by the job controller:

JBC-W-RESTRICT, UAF restricts access at this time, please log out immediately

Note that network connections are treated differently than interactive connections and batch jobs. See the documentation for the network software you are running for information about disconnecting established network connections.

7.8.3 Restricting CPU Time

OpenVMS Version 7.3 and later enables you to perform class scheduling using the SYSMAN interface.

You can limit the amount of CPU time that a user receives on the system by placing the user into a scheduling class. Each scheduling class is assigned a percentage of the overall CPU time on the system. As the system runs, the set of users in each scheduling class is limited to the percentage of CPU execution time allocated to that class. Users in a scheduling class can get additional CPU time if windfall is enabled for their scheduling class. Enabling windfall allows the system to give a small amount of CPU time to a scheduling class when a CPU is idle and the time alloted to that scheduling class has already been depleted.

To invoke the class scheduler, use the SYSMAN interface. SYSMAN allows you to create, delete, modify, suspend, resume, and display scheduling classes. Table 7-7 describes the SYSMAN command, class_schedule, and its sub-commands.

By using a permanent class scheduler, a process is placed into a scheduling class, if appropriate, at process creation time. When a new process is created, it needs to be determined whether this process belongs to a scheduling class. Since to determine this relies upon data in the SYSUAF file, and the Loginout image already has the process' information from this file, Loginout class schedules the process if it determines that the process belongs to a scheduling class.

When you use the SYSMAN command CLASS_SCHEDULE ADD, you can do the following:

• Create a scheduling class
• Identify users in the class, by account name, user name, or UIC
• Specify the percent of CPU time alloted to processes run by users in this scheduling class on primary days and secondary days and specify hourly ranges on during which the CPU time restriction applies
• Specify days as either primary days or secondary days, and specify different CPU time restrictions for primary days and secondary days
• Allow a scheduling class to receive additional CPU time when the CPU is idle

For example:

SYSMAN>
CLASS_SCHEDULE ADD MAINCLASS -
_SYSMAN> /ACCOUNT = (ACCTNAME1, ACCTNAME2) -
_SYSMAN> /USERNAME = HOTSHOT -
_SYSMAN> /CPU_LIMIT = (PRIMARY, 08-17=15, SECONDARY, 00-23=30) -
_SYSMAN> /WINDFALL

This example performs the following actions:

• Creates scheduling class MAINCLASS
• Adds users in accounts ACCTNAME1 and ACCTNAME2 to MAINCLASS
• Adds user HOTSHOT to MAINCLASS
• Allots processes run by users in MAINCLASS 15 percent of CPU time between 8 AM and 6 PM on primary days (default Monday through Friday)
• Allots processes run by users in MAINCLASS 30 percent of CPU time all day (24 hours) on secondary days (default SATURDAY and SUNDAY)
• Allows process run by users in MAINCLASS to receive extra CPU time during the specified days and times when the CPU is idle

Note that you can use the /PRIMEDAYS qualifier to change the primary and secondary days assigned to a scheduling class.

CPU time restrictions created with the class scheduler do not apply to system users (see Section 12.4.2).

For more detailed information about the SYSMAN CLASS_SCHEDULE command, see the OpenVMS System Management Utilities Reference Manual: M--Z.

7.8.4 Restricting Login Functions

In addition to specifying hourly login restrictions, you can assign function restrictions to an account by using appropriate keywords with the /FLAGS qualifier in the Authorize utility. By default, there are no restrictions. Options are shown in the following table:

Using the /LGICMD qualifier with the AUTHORIZE commands ADD, MODIFY, or COPY defines the login procedure for a restricted or captive account. A person logging in to such an account cannot modify the procedure with any of the login qualifiers: /CLI, /DISK, /COMMAND, /NOCOMMAND, /TABLES.

The CAPTIVE and RESTRICTED flags perform the following actions:

• Disable the use of Ctrl/Y (/FLAG=DISCTLY); however, a system manager can enable the Ctrl/Y sequence for a restricted account by adding the DCL command SET CONTROL=Y at the end of the login procedure.
• Prevent the use of the SPAWN command from Mail or the use of the SPAWN built-in procedure from the DEC Text Processing Utility (DECTPU).

Once logged in, a person using a restricted account operates from the DCL level and can access any available software.

A person using a captive account is locked into the application software where access to the DCL level is denied, provided the system manager observes the following practices:

• When you need to prompt for and accept direct user input, do not execute the text entered by the user directly; rather, first screen the input, and specifically permit only the set of characters that is valid for the intended use. Reject all characters that are not appropriate for the intended use.
  Prohibit the following character set from user input, as these characters have special meanings to the DCL command interpreter:

  ampersand (&) and double ampersand (&&)
  angle brackets (<) (>)
  apostrophe (')
  at-sign (@)
  dollar sign ($)
  hyphen (-)
  quotation mark (")
  semicolon (;)
  vertical bar (|) and double vertical bar (||)

• Use the DCL command READ/PROMPT in captive account login command procedures because the INQUIRE command is not allowed.
• Set the subprocess limit to 0 to prevent the user from spawning out of the account. Set both the /PRCLM qualifier and the SYSGEN parameter PQL_MPRCLM.

Example

A simple login command procedure for a captive account used for an inventory system might consist of the following commands:

$ DEFINE SYS$DISK DISK$INVENT
$ RUN INVENTORY
$ LOGOUT

The application program INVENTORY assumes control when the user logs in to the account. Assign the CAPTIVE flag to the login flags field of the captive account UAF record by specifying the AUTHORIZE qualifier /FLAGS=CAPTIVE. Section 7.7.4 shows how to use AUTHORIZE to create a UAF record for a captive account.

Example 7-4 is a command procedure for a highly secure captive account, which restricts the user to a very limited set of commands. System managers must be sure to deny the account owner any write access to the login command procedure and its directory. Note also that the security manager would use the AUTHORIZE qualifier /NOINTERACTIVE when establishing this account.

For more information about captive and restricted accounts, see the OpenVMS Guide to System Security.

$ deassign sys$input
$ previous_sysinput == f$logical("SYS$INPUT")
$ on error then goto next_command
$ on control_y then goto next_command
$ set control=(y,t)
$
$next_command:
$ on error then goto next_command
$ on control_y then goto next_command
$
$ if previous_sysinput .nes. f$logical("SYS$INPUT") then deassign sys$input
$ read/end=next_command/prompt="$ " sys$command command
$ command == f$edit(command,"UPCASE,TRIM,COMPRESS")
$ if f$length(command) .eq. 0 then goto next_command
$
$ delete = "delete"
$ delete/symbol/local/all
$ if f$locate("@",command) .ne. f$length(command) then goto illegal_command
$ if f$locate("=",command) .ne. f$length(command) then goto illegal_command
$ if f$locate("F$",command) .ne. f$length(command) then goto illegal_command
$ verb = f$element(0," ",command)
$
$ if verb .EQS. "LOGOUT" then goto do_logout
$ if verb .EQS. "HELP" then goto do_help
$
$ write sys$output "%CAPTIVE-W-IVVERB, unrecognized command \",verb,"\"
$ goto next_command
$
$illegal_command:
$ write sys$output "%CAPTIVE-W-ILLEGAL, bad characters in command line"
$ goto next_command
$
$do_logout:
$ logout
$ goto next_command
$
$do_help:
$ define sys$input sys$command
$ help
$ goto next_command

A user's priority is the base priority used in scheduling the process that the system creates for the user.

On VAX systems, priorities range in value from a low of 0 to a high of 31; 0 through 15 are timesharing priorities; 16 through 31 are real-time priorities.

On Alpha systems, priorities range in value from a low of 0 to a high of 63; 0 through 15 are timesharing priorities; 16 through 63 are real-time priorities.

Processes with real-time priorities are scheduled strictly according to base priority; in other words, the executable real-time process with the highest base priority is executed first. Processes with timesharing priorities are scheduled according to a slightly different principle to promote overlapping of computation and I/O activities.

In the user's account record of the UAF, the default value of a user's priority is 4; for practical purposes, the minimum value is 0. Ensure that the priority for timesharing users remains at the default. Note that if you give some users an advantage over other users by raising their priorities, ragged performance results, because the system reacts sharply to even small base priority differences.

7.9 Setting Up Special Accounts

As system manager, you might need to set up a variety of special accounts, such as automatic login accounts, project accounts, and proxy accounts. The following sections explain how to perform these tasks:

Section 7.9.3 explains what network proxy accounts are.

7.9.1 Setting Up an Automatic Login Account with SYSMAN

The System Management utility (SYSMAN) includes the functions of the automatic login facility (ALF). Using SYSMAN ALF commands, you can set up a terminal that automatically logs in a user to a certain user name. For example, a terminal might be set up for the account INVENTORY, which automatically logs in a user to a captive account when the user presses the Return key.

First, you must follow the steps described in the previous sections to create the top-level default directory and to add the account. Then you can associate the account with a particular terminal or port using the following format:

where:

To protect automatic login accounts, set the AUTOLOGIN flag in the account's UAF record. This flag makes the account available only by autologin, batch, and network proxy.

Examples

The following example shows how to invoke SYSMAN and assign terminal TTA0 to the INVENTORY25 account:

$ RUN SYS$SYSTEM:SYSMAN
SYSMAN> ALF ADD TTA0 INVENTORY25

When you create ALF records for proxy accounts, the device parameter can be as long as 63 characters. For example:

SYSMAN> ALF ADD VMS:.ZKO.VMSORG.SYSMAN.CLIENT1::SYSTEM FOOBAR

In this command, VMS:.ZKO.VMSORG.SYSMAN.CLIENT1::SYSTEM is the value of the device parameter.

For more information about autologin accounts and the SYSMAN ALF commands, see the OpenVMS System Management Utilities Reference Manual and the OpenVMS Guide to System Security.