To use the backup-while-open facility with CICS® VR, define DFSMSdss as the method DFSMShsm uses to move data.
SETSYS DATAMOVER(DSS)
When DFSMSdss performs a logical dump, it examines the backup-while-open flags in the integrated catalog facility (ICF) catalog and reports on the success or failure of the backup. For example, if a VSAM control interval (CI) or control area (CA) split is in progress at the start of a backup, the backup is not made. Also, if a split occurs during a backup-while-open backup, or a split is still in progress after a backup, the backup is logically discarded by DFSMShsm. If you are using DFSMSdss without DFSMShsm, examine the reports that DFSMSdss produces to find out if the logical dump has been successful. But, if you use the concurrent copy function with BWO, CI or CA splits do not affect the contents of the copy that is being made. See Using the concurrent copy function with CICS VR for more information.
Because the process of making backups can lead to increased I/O activity, consider making backups during periods of low activity. This would avoid an effect on the response time of the online application and reduce the probability of CI or CA splits.
For more information about DFSMSdss see z/OS® DFSMSdss Storage Administration Guide. For more information about DFSMShsm, see z/OS DFSMShsm Storage Administration Reference.
The master terminal operator (MTO) must be aware of any new environment. Before the availability of the backup-while-open facility, to backup a VSAM sphere, the MTO would quiesce all transactions that would update the data set, notify the users, and close and deallocate the necessary files. These procedures are not needed with the backup-while-open facility.
If this situation occurs, the following messages are issued, and the MTO must restore and recover the VSAM sphere to ensure data integrity:
If recovery was not run, you can run CICS VR to recover the VSAM data set. If the messages are issued because of the failure of CICS VR recovery, the MTO must restore and recover the associated VSAM sphere to ensure data integrity.
CEMT INQUIRE DSNAME
For more information, see CICS Supplied Transactions.