COMPACT: Specifying when compaction should be done

Explanation: COMPACT is an optional parameter set that you use to specify the type of compaction during migration or backup for all data sets.

The subparameters of the COMPACT parameter follow this discussion in alphabetical order. The following are optional subparameters:

ALL | NONE
DASDBACKUP
DASDMIGRATE
TAPEBACKUP
TAPEMIGRATE

SMS relationship: Parameter differs in meaning when applied to SMS-managed or non-SMS-managed DASD volumes or data sets. This COMPACT parameter is only used for SMS data sets that are not compressed on L0; as for non-SMS data sets, it's always in effect since you cannot have a non-SMS dataset compressed on L0.

SETSYS default: If you specify the COMPACT parameter without specifying any subparameters, the SETSYS default is no compaction.

DFSMShsm default: If you do not specify a subparameter with this parameter on any SETSYS command, the DFSMShsm default is no compaction.