Catalog considerations during ARECOVER processing

There are at least three states that the catalog environment can be in at the recovery location:

  1. The master and user catalogs exist at the recovery site with valid data set entries. You can issue the ARECOVER command with or without the DATASETCONFLICT(REPLACE) parameter. When you specify DATASETCONFLICT(REPLACE) parameter, be aware that you can unintentionally delete existing production data sets. If you do not specify DATASETCONFLICT(REPLACE), the data sets being recovered that have name conflicts are skipped during the recovery process.
    Note: If a catalog entry exists for a VSAM RLS data set, existing RLS attributes are maintained even if DSCONFLICT(REPLACE) was specified on the ARECOVER command.
  2. The Master and user catalogs exist at the recovery site but the data set entries are invalid. This means that either the volumes that are associated with a data set entry are not online or the volume does not contain a valid data set entry in the VTOC. This situation typically exists when catalogs have been previously recovered as part of a full volume dump and restore of the operating system volumes containing these catalogs.

    You can choose to issue the ARECOVER command with or without specifying the DATASETCONFLICT(REPLACE) parameter. If you do not specify DATASETCONFLICT(REPLACE), the data sets being recovered that have name conflicts are skipped during the recovery process. If you do specify DATASETCONFLICT(REPLACE), ARECOVER processing detects whether the catalog entry is valid or invalid. If the catalog entry is valid, a delete is issued for data sets in conflict before recovering the data set from the ABACKUP tapes. If the catalog entry is invalid, a DELETE NOSCRATCH is performed for data sets in conflict.

  3. You can choose to DEFINE a new catalog and associated aliases before you issue the ARECOVER command. Doing so allows ARECOVER processing to catalog data set entries when data sets are being recovered, and avoids any data set naming conflicts.

    A situation can occur where migrated data sets in the catalog but the migration volume does not exist at the recovery site. ARECOVER processing deletes conflicting data sets when the DATASETCONFLICT(REPLACE) parameter is specified, and DFSMShsm processing handles the situation where the migration volume is not online or the VTOC entry does not exist. If an ARC0184I message is issued when attempting to retrieve the MCV record for the migration volume, issue an ADDVOL command for the migration volume and reissue the ARECOVER command.

    It is possible that the catalog has entries for migrated data sets, but the MCD record does not exist in the MCDS. ARECOVER processing detects this situation and issues a DELETE NOSCRATCH for the migrated data set if the DATASETCONFLICT(REPLACE) parameter was specified on the ARECOVER command. This allows the migrated data set to be deleted and aggregate recovery processing to successfully recover the migrated data set encountering this situation.

  4. If you plan to recover the user catalogs specified in the ALLOCATE statement by using ARECOVER, and you have recovered the master catalog from the ABACKUP site that has alias entries for these user catalogs, it is best to first issue IDCAMS EXPORT DISCONNECT command before issuing the ARECOVER command to remove this connection.