SYSCTLG data sets can be migrated between like or unlike devices at several times the speed of IEHMOVE. A data set is treated as a system catalog when either the source and/or the target data set name is SYSCTLG. This permits the backing up of SYSCTLG data sets to DASD at high speed with the option of renaming the backup copy.
The capacity of the catalog can be changed significantly by preallocation of a larger SYSCTLG on the target volume. The migration support will format the additional space in the target allocation with empty catalog blocks, and update the TTR in the volume index control entry to reflect the additional capacity.
When a catalog is migrated between unlike device types, all TTR pointers in the catalog are converted. The conversion includes the validation of the TTR contained in the source catalog, and can detect either an invalid TTR or catalog entry type. These conditions cause the messages 425 and/or 426 to be issued, and the invalid block to be copied forward without modification. Although the invalid blocks are most likely disconnected, a machine comparison of the output from an IEHLIST of both the source and target catalogs can be used to validate the processing.
CA Disk does not disconnect the CVOL catalog from the VSAM master catalog. It also does not reconnect the CVOL catalog to the VSAM master catalog. The user with IDCAMS utilities must do this manually. For this reason the user should always consider the status of the catalog when CA Disk is moving it. Where are the catalog entries for the data sets being moved? If the catalog is being moved in the same run, it is possible that some data sets will lose their new catalog status because the catalog was copied to a new volume, but data sets copied subsequent to the catalog move were still being cataloged in the old copy of the catalog.
It is recommended that CVOL catalogs be moved as a separate operation, either before or after all other data sets are moved, but not within the same process. After a CVOL catalog has been moved, ensure that all of its connecting entries to the master catalog are rebuilt immediately.
To assist you in disconnecting and reconnecting a CVOL catalog that has been moved to a new volume, the following sample commands for the IDCAMS utility are provided. Consult your IBM IDCAMS manual for more specific information.
To delete high-level index pointers from your master catalog to your old CVOL (on the old volume), use commands similar to the following for each high level index:
DELETE (INDEX1) ALIAS
To define a new CVOL catalog in your master catalog:
DEFINE NONVSAM (NAME(SYSCTLG.V______) DEVT( ) VOL( ))
To reconnect the high-level index pointers to the CVOL catalog on the new volume:
DEFINE ALIAS (NAME(INDEX1) RELATE(SYSCTLG.V______))
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