POOL: Identifying the non-SMS-managed volumes where the data sets with the same first qualifier are recalled

Explanation: POOL is an optional parameter specifying the set of initial characters of the data set name for a group of data sets and the set of non-SMS-managed volumes where the group of data sets is to be recalled. Each poolid and associated volume list is a user-defined pool. When recall occurs, the set of initial characters of the data set name forces the recall of those data sets to one of the specific volumes identified with the VOLUMES subparameter. To remove the association between a pool ID and its associated volumes from pool control, you omit the VOLUMES subparameter when you specify POOL.

POOL(poolid): For poolid, substitute the set of initial characters of the data set name of those data sets you want recalled to the specified volume or volumes. The poolid can end with a period if POOL is the first keyword on the command.

Subparameter	Explanation
VOLUMES	POOL(poolid VOLUMES(volser ...)) specifies the volumes where the data sets with the set of initial characters specified with the POOL parameter are recalled. When you specify multiple volumes for a pool ID, DFSMShsm tries to recall data sets to the volume with the most space. If there is not enough space on the volume, DFSMShsm can try recalling the data set to up to four different volumes from the same pool. For volser ..., substitute the serial numbers of the volumes where the group of data sets is to be recalled.

Subparameter

Explanation

VOLUMES

POOL(poolid VOLUMES(volser ...)) specifies the volumes where the data sets with the set of initial characters specified with the POOL parameter are recalled. When you specify multiple volumes for a pool ID, DFSMShsm tries to recall data sets to the volume with the most space. If there is not enough space on the volume, DFSMShsm can try recalling the data set to up to four different volumes from the same pool.

For volser ..., substitute the serial numbers of the volumes where the group of data sets is to be recalled.

Defaults: None.

Note:

When DFSMShsm checks whether a data set belongs to a pool, it checks the pools in the order you defined them and chooses a pool whose ID matches the initial characters of the data set name. If you define pools, so one is a subset of the other such as MYDSN and MYDSNAME, define the more restrictive pool first (in this case, MYDSNAME) as shown in the following example:
```
   DEFINE POOL(MYDSNAME VOLUMES(VOL001))
   DEFINE POOL(MYDSN VOLUMES(VOL002 VOL004))
```
If you do not define the pools in the order shown in the example, as soon as DFSMShsm sees the MYDSN part of MYDSNAME, it finds a match, and chooses VOL002 even if you wanted to use VOL001.
The JES3 considerations contains detailed information about defining pools in a JES3 environment.
You can specify up to 140 volumes.
If an SMS-managed volume is specified as part of a data set pool, a message is issued indicating that the volume was not added to the data set pool. Processing continues for the DEFINE command. If, however, only SMS-managed volumes are specified for the definition of the data set pool, the data set pool definition is rejected and the DEFINE command fails.
Volumes specified in the DEFINE POOL command must also be added as primary volumes. To do this, use of the ADDVOL command.