RECOVER command: Recovering a backup version or dump copy of a data set or a volume

The RECOVER command causes DFSMShsm to invoke DFSMSdss to do a physical restore of the requested data set or volume when you specify the FROMDUMP parameter with the command. If you also specify the APPLYINCREMENTAL parameter with the RECOVER command (following the restore), DFSMShsm recovers data sets incrementally backed up by DFSMShsm if backup occurred after the dump. You can tell DFSMShsm to use a particular dump copy as the source of the restore by specifying one of the following parameters with the RECOVER command:

DATE
DUMPCLASS
DUMPGENERATION
DUMPVOLUME

When the RECOVER command is issued without the FROMDUMP parameter, DFSMShsm recovers a level 0 volume, or an incremental backup version of a data set, or a dump copy of a data set, depending on which copy is more current. If there are no records of the data set in the BCDS, and there is no catalog entry for the data set on the volume from which the dump copy was made, the recovery fails. If a dump copy of the data set exists, a RECOVER command issued with the FROMDUMP parameter could successfully recover the data set.

When FROMDUMP DUMPVOLUME is not specified, the restore of a multiple striped data set will be from an incremental backup version. If no incremental backup version exists, the restore will fail. To restore an extended format data set from a dump volume, the FROMDUMP DUMPVOLUME parameter must be used for each extended format data set.

You can use the recovered version of the data set to replace an existing data set. You can also rename the recovered version to have two versions of the same data set. If you want to recover backup versions of a migrated data set, use one of the following procedures:

Recall the migrated data set and recover a backup version of that data set.
Delete the migrated data set and recover a backup version of the deleted data set.
Specify the NEWNAME parameter and recover a backup version of that data set. The NEWNAME parameter cannot be the name of a migrated data set.
If none of the above three procedures works, use the FIXCDS command to delete the MCDS data set (MCD) record for the migrated data set and uncatalog the data set. Then recover the backup version of the data set.

You normally run volume recovery when an entire DASD pack has been lost or damaged or when a significant amount of the data is no longer accessible.

If a data set being recovered spans to a second or more volumes, and the data set resides on disaster alternate volumes that are in a tape library, DFSMShsm will verify and correct the tape library volume record for the first volume and the original volumes in the volume list only. The message ARC0184I RC=4 is issued for all other volumes that are disaster alternate volumes. The message ARC0184I RC=4 is issued for an MCT record that cannot be found for the disaster alternate volume.

Disaster alternate volumes do not have MCT records. The MCT is for an original volume only. The message ARC0184I RC=4 is not an indication of an error condition for a disaster alternate volume. The disaster alternate volume will be allocated and the recovery process will continue.

This following example shows a volume list for a data set spanning four volumes.

   TAPEA - DISASTER ALTERNATE VOLUME - TAPE LIBRARY RECORD VERIFIED.
   TAPEB - DISASTER ALTERNATE VOLUME - MESSAGE ARC0184I RC=4.
   TAPEC - ORIGINAL TAPE VOLUME - TAPE LIBRARY RECORD VERIFIED.
   TAPED - DISASTER ALTERNATE VOLUME - MESSAGE ARC184I RC=4.

When replacing an existing SMS-managed data set, DFSMShsm normally recovers or restores the data set to the volume on which the data set is currently cataloged; however, for SMS-managed VSAM data sets, VTOC/Data Set Services selects the target volume. In addition, the SMS class names that currently exist in the catalog for the data set are maintained, regardless of what the class names were at the time of backup or dump.

When recreating a deleted data set, DFSMShsm determines a new class name by invoking the ACS routines. The result of invoking ACS determines if the data set is to be SMS-managed, VTOC/Data Set Services chooses the target volume, and the newly determined class name is associated with the data set.

The exception to the above rules for replacing and recreating SMS-managed data sets is when the FORCENONSMS parameter is issued with the RECOVER command. The FORCENONSMS parameter can force recovery of an SMS-managed data set to a non-SMS-managed volume. It is not possible to convert a data set that is not extended format to a data set that is extended format during recovery. However, you can convert an extended format data set to a data set that is not extended format during a recovery, if you specify the FORCENONSMS optional parameter.

If the dump data was encrypted with a password and DFSMShsm will be used to recover the dump, then DFSMShsm will automatically send the encryption password to DFSMSdss to decrypt the data during recovery. If the dump data will be recovered with DFSMSdss directly, then use the LIST DUMPVOLUME command to determine which password should be specified on the DFSMSdss RESTORE command. If the dump data was encrypted with a RSA key label, the data will automatically be decrypted upon recovery if the recovery is performed within the same encryption environment as the dump was created. If the encryption environment has changed or the recovery is being performed in a different environment, the appropriate RSA key label must be specified on the DFSMShsm RECOVER or DFSMSdss RESTORE command.

The REPLACE subparameter is required when replacing an existing data set.

RECOVER command: Recovering a backup version or dump copy of a data set or a volume

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