Fixing Temporary Catalog Problems

Operator Commands Discussed in This Section:

MODIFY CATALOG,ABEND
MODIFY CATALOG,CLOSE
MODIFY CATALOG,END
MODIFY CATALOG,RESTART
MODIFY CATALOG,UNALLOCATE
MODIFY CATALOG,VCLOSE
MODIFY CATALOG,VUNALLOCATE

Occasionally, the control blocks for a catalog kept in the catalog address space might be damaged. You might think the catalog is damaged and in need of recovery, when only the control blocks need to be rebuilt. If the catalog appears damaged, try rebuilding the control blocks first. If the problem persists, recover the catalog.

There might also be situations where a job gets an enqueue lockout from a catalog, or a catalog request is not being satisfied for some reason. In these cases, the job needs to be ended and redriven, if possible.

It is also possible that a catalog request that is currently being processed, cannot be properly retried after being interrupted by these commands. Use these commands when all other means of correcting an ongoing catalog error have failed.

Table 1 gives an overview of the error recovery capabilities of the MODIFY CATALOG command.

Table 1. Error Recovery Capabilities of MODIFY CATALOGS
Option	Purpose
ABEND	To end a CAS task abnormally. This should only be used after you have unsuccessfully tried END, or when you are ending the CAS allocate, analysis, or modify tasks.
CLOSE	To release all CAS storage for the specified catalog. The catalog is not locked, and is re-opened to CAS by the next catalog request that accesses the catalog. The catalog is not unallocated from CAS, and the common services area storage used by the catalog is not freed.
END	To end a CAS task. You can choose to redrive the request, or simply end it. This is the preferred method of ending a CAS task, and should be used before attempting ABEND.
RESTART	To abnormally end the CAS mother task and restart it in a new address space. This option should only be used when your only other option is to IPL the system. If RESTART fails, you must IPL.
UNALLOCATE	To unallocate and close a catalog allocated to CAS from CAS without releasing the CAS storage. As with CLOSE, the control blocks for the catalog are rebuilt with the next request for the catalog, and the catalog is not locked. This command is useful for getting a volume offline.
VCLOSE	To close the VVDS that resides on the specified volume. The VVDS is opened by the next request that tries to access it.
VUNALLOCATE	To unallocate all VVDSs from the catalog address space. This can help in getting a volume offline for recovery. The VVDS is not locked, and the next request that tries to access it opens the VVDS. However, VVDSs are not allocated to the catalog address space until MODIFY CATALOG,NOVUNALLOCATE is issued.
Note: This table does not reflect the detailed syntax of these commands. See MODIFY CATALOG Command Syntax for syntax information.