DEFINE STGCLASS on z/OS
Use the MQSC command DEFINE STGCLASS to define a storage class to page set mapping.
Use MQSC commands
For information on how we use MQSC commands, see Performing local administration tasks using MQSC commands.
We can issue this command from sources 2CR. For an explanation of the source symbols, see Use commands on z/OS®.
Synonym: DEF STC
Values shown above the main line in the railroad diagram are the defaults supplied with IBM MQ , but your installation might have changed them. See Syntax diagrams.DEFINE STGCLASS
Notes:- 1 Valid only on z/OS when the queue manager is a member of a queue-sharing group.
Usage notes for DEFINE STGCLASS
- The resultant values of XCFGNAME and XCFMNAME must either both be blank or both be nonblank.
- We can change a storage class only if it is not being used by any queues. To determine whether
any queues are using the storage class, we can use the following command:
DISPLAY QUEUE(*) STGCLASS(ABC) PSID(n)
where 'ABC' is the name of the storage class, and n is the identifier of the page set that the storage class is associated with.
This command gives a list of all queues that reference the storage class, and have an active association to page set n, and therefore identifies the queues that are actually preventing the change to the storage class. If we do not specify the PSID, you just get a list of queues that are potentially stopping the change.
See the DISPLAY QUEUE PSID command for more information about active association of a queue to a page set.
Parameter descriptions for DEFINE STGCLASS
- (storage-class)
-
Name of the storage
class.
This name is one to 8 characters. The first character is in the range A through Z; subsequent characters are A through Z or 0 through 9.
Note: Exceptionally, certain all numeric storage class names are allowed, but are reserved for the use of IBM service personnel.The storage class must not be the same as any other storage class currently defined on this queue manager.
- CMDSCOPE
-
This parameter
specifies how the command runs when the queue manager is a member of a queue sharing group.
CMDSCOPE must be blank, or the local queue manager, if QSGDISP is set to GROUP.
- ' '
- The command runs on the queue manager on which it was entered.
- qmgr-name
- The command runs on the queue manager you specify, providing the queue manager is active within
the queue sharing group.
We can specify a queue manager name other than the queue manager on which it was entered, only if you are using a shared queue environment and if the command server is enabled.
- *
- The command runs on the local queue manager and is also passed to every active queue manager in the queue sharing group. The effect of * is the same as entering the command on every queue manager in the queue sharing group.
- DESCR( description )
-
Plain-text comment. It
provides descriptive information about the object when an operator issues the DISPLAY STGCLASS
command.
It must contain only displayable characters. The maximum length is 64 characters. In a DBCS installation, it can contain DBCS characters (subject to a maximum length of 64 bytes).
Note: If characters are used that are not in the coded character set identifier (CCSID) for this queue manager, they might be translated incorrectly if the information is sent to another queue manager - LIKE( stgclass-name )
-
The name of an object of
the same type, with parameters that are used to model this definition.
If this field is not completed, and we do not complete the parameter fields related to the command, the values are taken from the default definition for this object.
Not completing this parameter is equivalent to specifying:LIKE(SYSTEMST)
This default storage class definition can be altered by your installation to the default values required.
The queue manager searches for an object with the name you specify and a disposition of QMGR or COPY. The disposition of the LIKE object is not copied to the object you are defining. Note:- QSGDISP (GROUP) objects are not searched.
- LIKE is ignored if QSGDISP(COPY) is specified.
- PASSTKTA( application name )
- The application name that is passed to RACF® when authenticating the PassTicket specified in the MQIIH header.
- PSID( integer )
-
The page set identifier
that this storage class is to be associated with. Note: No check is made that the page set has been
defined; an error is raised only when you try to put a message to a queue that specifies this
storage class (MQRC_PAGESET_ERROR).
The string consists of two numeric characters, in the range 00 through 99. See DEFINE PSID on z/OS.
- QSGDISP
- Specifies the disposition of the object in the group.
QSGDISP DEFINE COPY The object is defined on the page set of the queue manager that executes the command using the QSGDISP(GROUP) object of the same name as the 'LIKE' object. GROUP The object definition resides in the shared repository but only if the queue manager is in a queue sharing group. If the definition is successful, the following command is generated and sent to all active queue managers in the queue sharing group to attempt to make or refresh local copies on page set zero: DEFINE STGCLASS(storage-class) REPLACE QSGDISP(COPY)
The DEFINE for the group object takes effect regardless of whether the generated command with QSGDISP(COPY) fails.PRIVATE Not permitted. QMGR The object is defined on the page set of the queue manager that executes the command. - REPLACE and NOREPLACE
-
Whether the existing
definition, and with the same disposition, is to be replaced with this one. Any object with a
different disposition is not changed.
- REPLACE
- The definition replaces any existing definition of the same name. If a definition does not
exist, one is created.
If we use the REPLACE option, all queues that use this storage class must be temporarily altered to use another storage class while the command is issued.
- NOREPLACE
- The definition does not replace any existing definition of the same name.
- XCFGNAME( group name )
-
If you are using
the IMS bridge, this name is the name of the XCF group to which the IMS system belongs. (This name is the group name specified in
the IMS parameter list.)
This name is 1 - 8 characters. The first character is in the range A through Z; subsequent characters are A through Z or 0 - 9.
- XCFMNAME( member name )
-
If you are using
the IMS bridge, this name is the XCF member name of the IMS system within the XCF group specified in XCFGNAME. (This
name is the member name specified in the IMS
parameter list.)
This name is 1 - 16 characters. The first character is in the range A through Z; subsequent characters are A through Z or 0 - 9.