Allocating backup data sets

Whether you choose DFSMSdss or IDCAMS as the data mover when copying the control data sets, the backup data sets are allocated in the following manner:

If backing up to DASD, you must preallocate the backup data sets.
If backing up to tape, the data sets are dynamically allocated by DFSMShsm.

The backup data set names are given a low-level qualifier of either Dxxxxxxx (if DFSMSdss is used for copying) or Vxxxxxxx (if IDCAMS is used for copying), where xxxxxxx is the version number. Backup data set names for multicluster CDS data sets are given a low-level qualifier of DSy.Dxxxxxxx, where y is the volume number and xxxxxxx is the version number. When CDS version backup fails, the data set name of the failed backup is given a low-level qualifier of Xxxxxxxx, where xxxxxxx is the version number. This data set naming convention supports the use of automated CDS-recovery procedures that determine the latest good control data set backup versions from catalog information.