With either of the preceding VSAM SHAREOPTIONS, a data integrity exposure could still exist if DFSMShsm is not active in all connected processors. Therefore, strictly controlled procedures need to be in place for doing periodic maintenance on the CDSs. Example: If either of the VSAM SHAREOPTIONS has been defined and the CDSs are on shared DASD, a DFSMShsm system can be started on one processor while a utility job is reorganizing the CDSs on another processor. Problems can be avoided by allocating the utility job with a disposition of OLD, which causes an exclusive enqueue on the SYSDSN resource for the CDS cluster name. Because DFSMShsm must have a shared enqueue on the same resource, this approach prevents DFSMShsm from running at the same time as the utility in a GRS environment. See HSMPRESS for a sample listing of a utility job that allocates with the disposition of OLD.

After processing has been completed, DFSMShsm releases the volumes.