Controlling automatic reuse of dump tapes

The AUTOREUSE subparameter of the DUMPCLASS parameter controls whether dump tapes that have a retention period specified for them in the dump class are reused when the data expires. AUTOREUSE specifies that the tapes are returned to the DFSMShsm tape pool when the dump copy is invalidated. NOAUTOREUSE specifies that the tapes are marked as unavailable for selection by DFSMShsm when the dump copy is invalidated.

Because the volumes in dump class ONEWEEK are retained at the computer site, they can be reused when the data on them is invalidated. Therefore, begin building the DEFINE DUMPCLASS command to be added to the ARCCMDxx member in each host for this dump class as:

DEFINE DUMPCLASS(ONEWEEK AUTOREUSE)

Because the volumes in dump classes TWOWEEK and FOURWEEK are sent to another site, they cannot be automatically returned to use by the system. Therefore, add the following DEFINE DUMPCLASS commands to the ARCCMDxx member in each host for these dump classes:

DEFINE DUMPCLASS(TWOWEEK NOAUTOREUSE)
DEFINE DUMPCLASS(FOURWEEK NOAUTOREUSE)

The AUTOREUSE subparameter is really of use only when you specify that empty tapes be returned to a DFSMShsm pool of empty tapes that are known to DFSMShsm. If tapes are returned to the scratch pool and if you are not selecting specific tapes for subsequent output tape selection, this subparameter is of no use because it makes tapes reusable only if they are known to DFSMShsm.

In the example system, scratch tapes are used and empty tapes are released to the scratch pool. Therefore, although the specification of AUTOREUSE for dump class ONEWEEK was shown, it has no effect because volumes are not being defined to DFSMShsm. However, the reason for specifying NOAUTOREUSE in dump classes TWOWEEK and FOURWEEK is valid. NOAUTOREUSE must be specified for tapes that are taken away from the computer system site.