Change Subsystem Description (CHGSBSD)

The Change Subsystem Description (CHGSBSD) command changes the operational attributes of the specified subsystem description. You can change the subsystem description while the subsystem is active. However, you cannot specify the *RMV value on the Storage pools (POOLS) parameter while the subsystem is active, because a job may become suspended.

Restrictions:

1. To use this command, you must have:
   • object operational (*OBJOPR), object management (*OBJMGT), and read (*READ) authority to the specified subsystem description and execute (*EXECUTE) authority to the library containing that subsystem description.
   • all object (*ALLOBJ) and security administration (*SECADM) special authority to specify a system library list entry.
   • all object (*ALLOBJ) and security administration (*SECADM) special authority to specify an auxiliary storage pool (ASP) group name.
2. You cannot specify the *RMV value on the POOLS parameter while the subsystem is active, because a job may become suspended.
3. You cannot change the value of the ASPGRP parameter while the subsystem is active.

Parameters

Subsystem description (SBSD)

Specifies the name and library of the subsystem description being changed.

This is a required parameter.

Qualifier 1: Subsystem description

name

Specify the name of the subsystem description being changed.

Qualifier 2: Library

*LIBL

All libraries in the thread's library list are searched until a match is found.

*CURLIB

The current library for the thread is used to locate the object. If no library is specified as the current library for the thread, the QGPL library is used.

name

Specify the library where the subsystem description is located.

Storage pools (POOLS)

Specifies the identifiers of one or more storage pool definitions and the changes that are made to them.

When an existing pool definition is removed, the subsystem must be inactive.

The size and activity level of each existing pool definition that is not specified, does not change.

Single values

*SAME

The storage pool definitions in the subsystem description do not change.

Other values (up to 10 repetitions)

Element 1: Pool identifier

1-10

Specify the pool identifier of the storage pool definition to be changed.

Element 2: Storage size

*BASE

The specified pool definition is defined to be the base system pool, which can be shared with other subsystems. The minimum size and activity level of the base pool are specified in the system values QBASPOOL and QBASACTLVL.

*NOSTG

No storage and no activity level are assigned to the pool at first. (It is inactive.)

*RMV

The specified pool definition is removed from the subsystem description.

*INTERACT

The specified pool definition is defined to be the shared pool used for interactive work. The size and activity level of the shared pool are specified using the Change Shared Storage Pool (CHGSHRPOOL) command.

*SPOOL

The specified pool definition is defined to be the shared pool used for spooled writers. The size and activity level of the shared pool are specified using the CHGSHRPOOL command.

*SHRPOOLnn

The specified pool definition is defined to be a general-purpose shared pool. There are sixty general-purpose shared pools, identified by special values *SHRPOOL1 to *SHRPOOL60. The size and activity level of a shared pool are specified using the CHGSHRPOOL command.

integer-number

Specify the storage size of the specified storage pool. A value of at least 256 kilobytes must be specified. The size is specified in kilobytes or megabytes by using element 4: Size unit of measure.

Note: Changes to the size of a pool may require pages to be written to auxiliary storage. The time required for the system to complete a large change may be greater than your default wait time. If this occurs, message CPF1001 (Wait time expired for system response.) is issued, even though the change completes.

Element 3: Activity level

integer-number

Specify the maximum number of threads that can run at the same time in the pool.

Element 4: Size unit of measure

*KB

The specified storage size of the pool is in kilobytes units.

*MB

The specified storage size of the pool is in megabytes units.

Maximum jobs (MAXJOBS)

Specifies the maximum number of jobs that can be active at the same time in the subsystem controlled by this subsystem description. The maximum applies to all jobs that are started and are waiting or running, except for jobs on the job queue or jobs that have finished running.

*SAME

The maximum number of jobs allowed at the same time in the subsystem does not change.

*NOMAX

There is no maximum number of jobs allowed at the same time in this subsystem.

0-32000

Specify the maximum number of jobs allowed in this subsystem.

Text 'description' (TEXT)

Specifies the text that briefly describes the object.

*SAME

The text, if any, does not change.

*BLANK

No text is specified.

character-value

Specify no more than 50 characters of text, enclosed in apostrophes.

Sign-on display file (SGNDSPF)

Specifies the name and library of the sign-on display file that is used when showing sign-on displays at work stations allocated to the subsystem. If the specified sign-on display file does not exist when the subsystem description is created or changed, you must specify a library qualifier because the qualified sign-on display file name is kept by the system. The sign-on display file must contain a record format named SIGNON.

Note: The sign-on display file can be changed when the subsystem is active. However, the new sign-on display file is not used until the next time the subsystem is started.

Note: Use (*USE) is needed to complete format checks of the display file. This helps predict that the display will work correctly when the subsystem is started. If you are not authorized to the display file or its library, those format checks will not be performed.

Single values

*SAME

The current sign-on display file value does not change.

*QDSIGNON

The sign-on display file value QDSIGNON in QSYS is used when showing sign-on displays at work stations that are allocated to the subsystem.

Qualifier 1: Sign-on display file

name

Specify the name of the sign-on display file that is used.

Qualifier 2: Library

*LIBL

All libraries in the thread's library list are searched until a match is found.

*CURLIB

The current library for the thread is used to locate the object. If no library is specified as the current library for the thread, the QGPL library is used.

name

Specify the library where the sign-on display file is located.

Subsystem library (SYSLIBLE)

Specifies a library that is added ahead of other libraries in the system portion of the library list of jobs started in the subsystem. This parameter allows you to use a secondary language library.

Restrictions:

1. This parameter can be changed while the subsystem is active. Any changes you make take effect for new jobs that are started. The library list of active jobs within the subsystem is not changed.
2. The secondary language library should not be specified in the QSYSLIBL or QUSRLIBL system values. QSYSLIBL must contain fewer than 15 libraries to allow the secondary language library to be added to the system portion of the library list.
3. You must have *ALLOBJ and *SECADM special authority to specify a value other than *NONE for a system library list entry.

*SAME

The system library list is not changed.

*NONE

The secondary language library is removed from the system library list.

name

Specify the name of the library being added to the system library list.

ASP group (ASPGRP)

Specifies the name of an auxiliary storage pool (ASP) group to be included in the library name space of the subsystem monitor job. The ASP group name is the name of the primary ASP device within the ASP group.

When the subsystem monitor job creates a user job, the job description is found using the library name space of the subsystem monitor job. Job queues, the sign-on display file, and the subsystem library are found in the library name space of the subsystem monitor job.

When the subsystem monitor job is doing work on behalf of a user job, the subsystem uses the library name space of the user job. The program and class are found in the library name space of the user job. For these objects, the ASPGRP parameter in the subsystem description has no effect.

When a subsystem monitor job uses an ASP group, the jobs in that subsystem should use the same ASP group. Use the Initial ASP group (INLASPGRP) parameter for the job description so that the ASP group is set during job creation and can be used to find other objects during job creation. Consistency between the subsystem monitor job and the user job is particularly important for prestart job entries because there are times the subsystem must find the program in order to determine which job description to use.

Restrictions:

1. The library name space of the subsystem monitor job for the controlling subsystem cannot include an ASPGRP. If a value other than *NONE is specified in the subsystem description for the controlling subsystem, it is ignored.
2. The library name space of the subsystem monitor job for the QSYSWRK subsystem cannot include an ASPGRP. If a value other than *NONE is specified in the subsystem description for the QSYSWRK subsystem, it is ignored.
3. The ASP group must be varied on and have a status of 'Available' before the subsystem is started.
4. The subsystem must be ended before the ASP group can be varied off.
5. This parameter cannot be changed while the subsystem is active.

*SAME

The ASP group value is not changed.

*NONE

The library name space of the subsystem monitor job will not include an ASP group.

name

Specify the name of the ASP group to be included in the library name space of the subsystem monitor job.

Workload group (WLCGRP)

Specifies the name of a workload group to be used for jobs in the subsystem.

Restrictions:

1. This parameter can be changed while the subsystem is active. Any changes you make take effect for new jobs that are started. The workload group of active jobs within the subsystem is not changed.
2. The controlling subsystem does not use a workload group for jobs in the controlling subsystem. If a value other than *NONE is specified in the subsystem description for the controlling subsystem, it is ignored.

*SAME

The workload group value is not changed.

*NONE

A workload group will not be used for jobs in the subsystem.

name

Specify the name of the workload group to be used for jobs in the subsystem.

Examples

Example 1: Changing Storage Size and Activity Level

CHGSBSD   SBSD(QGPL/PAYCTL)  POOLS((2 1500 3))
          SGNDSPF(QGPL/COMPANYA)

This command changes the definition of storage pool 2 that is used by subsystem PAYCTL to a storage size of 1500K and an activity level of 3. The sign-on display file is changed to display file COMPANYA and is located in the QGPL library. If the subsystem is active when this command is issued, COMPANYA is not used until the next time the subsystem is started.

Example 2: Changing Multiple Attributes

CHGSBSD   SBSD(LIB6/ORDER)
          POOLS((1 *BASE)(2 750 4)(3 *RMV)(4 *NOSTG))
          MAXJOBS(5)

This command changes the maximum number of jobs that subsystem ORDER can support to five. (The description of the subsystem is stored in library LIB6.) The definition of storage pool 1 is changed to the base shared system pool, the definition of pool 2 is changed to have a storage size of 750K and an activity level of 4, the definition of pool 3 is removed from the subsystem, and the definition of pool 4 is changed to have no storage and no activity level.

Example 3: Changing the Language Library

CHGSBSD   SBSD(QGPL/SPANISH)  SGNDSPF(QSYS2931/QDSIGNON)
          SYSLIBLE(QSYS2931)

This command changes subsystem description SPANISH to a Spanish secondary language.

Error messages

*ESCAPE Messages

CPF1619

Subsystem description &1 in library &2 damaged.

CPF1691

Active subsystem description may or may not have changed.

CPF1697

Subsystem description &1 not changed.