You can use DFSMSdss and the concurrent copy function to back up the control data sets. Concurrent copy lets you make a point in time copy of a control data set even while it is being updated. DFSMSdss also validates the CDS while the CDS is being backed up. This function is similar to AMS EXAMINE.
The use of the concurrent copy function will reduce the duration of complex-wide serialization of the DFSMShsm CDS resources when performing CDS version backup and, when SETSYS JOURNAL(RECOVERY) is specified, non-intrusive journal backup is used to further reduce the duration (see Using non-intrusive journal backup). This time reduction increases the availability of DFSMShsm functions and non-intrusive journal backup allows DFSMShsm activity to continue during the journal backup. To achieve the highest level of DFSMShsm availability, you should place the control data sets on SMS-managed devices that support the concurrent copy function, and you should use DFSMSdss to back up the control data sets. If DFSMSdss backs up to tape, each CDS (or each cluster if multi-cluster control data sets are used) is copied to an individual tape drive (in parallel). Use of concurrent copy is required in order to use non-intrusive journal backup.
If a control data set is on an SMS-managed device that supports the concurrent copy function, and the management class attribute BACKUP COPY TECHNIQUE is specified as a value other than STANDARD, DFSMSdss establishes a concurrent copy session. (See Concurrent copy management class support for information about the BACKUP COPY TECHNIQUE management-class attribute.) Otherwise, DFSMShsm directs DFSMSdss to dump the data set without the benefit of concurrent copy. All control data sets, if they are SMS-managed, should be specified with the same SMS backup copy technique.
After all resources have been set up (data sets allocated and tapes mounted), the control data sets are reserved. When using RLS in a multihost environment, DFSMShsm does an exclusive enqueue rather than a reserve. The reserves, or enqueues, prevent other DFSMShsm functions that require the control data sets from running.
DFSMShsm removes the CDS serialization after the following actions have been done:
All current DFSMShsm-supported backup DASD and tape devices are supported by the concurrent copy function.