Plan to use the DFSMSrmm utilities EDGBKUP and EDGHSKP to back up the control data set. You can automatically back up the control data set as part of inventory management if you use EDGHSKP which also clears the journal. You can also use the parmlib OPTION command JOURNALFULL operand threshold value to start a backup procedure.

Back up the control data set to DASD. You can also back up the control data set to tape using DFSMSdss. Once the backup is complete, you can move or copy the backup file to any storage medium.

DFSMSrmm Support for Copy Services: When you use XRC, PPRC, Metro or Global Mirror, or other DASD subsystem facilities for maintaining a copy of the DFSMSrmm CDS, you must plan some minimal recovery actions to ensure that the CDS copy used in recovery situations is a consistent copy of the CDS. A consistent copy ensures that there is no multi-record update in progress and that any transaction to update the CDS has been completed. You should also mirror the DFSMSrmm journal and use this for forward recovery of the mirrored CDS copy to make it consistent.

Alternatively, you can use a DFSMSrmm utility to initiate the creation of a CDS copy at the data set level. EDGHSKP and EDGBKUP provide a COPY option that requests DFSMSrmm use DFSMSdss COPY. By default, DFSMSrmm attempts fast replication, but you can tailor the COPY command used to meet your needs. A CDS copy created in this way is already a consistent copy of the CDS and needs no further processing to enable use by DFSMSrmm, unless you need to forward recover to a specific point in time.

When you use DFSMSrmm forward recovery support in the EDGBKUP utility, you can specify a specific point in time to which the CDS should be recovered, or you can forward recover to the latest consistent set of CDS records. Forward recovery uses journal records from journal backups and the active journal, or can optionally use DFSMSrmm SMF type 42 records.

When you plan to switch to a mirrored copy of the CDS, you must plan to run the EDGBKUP utility with forward recovery using a mirrored copy of the DFSMSrmm JOURNAL data set. This ensures that the CDS copy is forward recovered to the latest consistent set of journal records. This might include records that have been successfully journaled, but not yet updated in the CDS. These journaled records can be used recover the latest level of the CDS.

Recommendation: Keep the latest backup available on DASD to provide the fastest recovery time for the control data set.

See Backing up the control data set for more information.