Control data set and journal data set backup copies

The control data set (CDS) and journal data set backup copies provide you with the ability to conduct on-site recovery should any of the control data sets become lost or damaged. The CDS and journal backup copies are optional but are highly recommended because they enable you to reconstruct your control data sets to the point of failure.

Control Data Set Backup Copies

Required:: No, but highly recommended.
Allocated by starter set:: Yes, see Starter set example.
Data set type:: Physical sequential.
Storage guidance:: Do not allow DFSMShsm to inadvertently migrate or backup your control data set and journal data set backup copies. If the CDS and journal backups are placed on DFSMShsm-managed volumes, ensure that policies are in place to prevent their migration or backup.
For information on the methods to back up the control data sets, see "Phase 1: Backing up the control data sets" in z/OS DFSMShsm Storage Administration.