System-level backups for object-level recoveries

If a system-level backup is chosen as a recovery base for an object, DFSMShsm is invoked by the RECOVER utility. This process restores the data sets for the object from the system-level backup of the database copy pool.

You need to set subsystem parameter SYSTEM_LEVEL_BACKUPS to YES so that the RECOVER utility will consider system-level backups.

  • If the system-level backup resides on DASD, it is used for the restore of the object.
  • If the system-level backup no longer resides on DASD, and has been dumped to tape, then the dumped copy is used for the restore of the object if FROMDUMP was specified.

Message DSNU1520I is issued to indicate that a system-level backup was used as the recovery base.

If DFSMShsm cannot restore the data sets, message DSNU1522I with reason code 8 is issued. If OPTIONS EVENT(ITEMERROR,SKIP) was specified, the object is skipped and the recovery proceeds on the rest of the objects. Otherwise, the RECOVER utility terminates.

If you specify YES for the RESTORE/RECOVER FROM DUMP option on installation panel DSNTIP6 or if you specify the FROMDUMP option on the RECOVER utility statement, then only dumps on tape of the database copy pool are used for the restore of the data sets. In addition, if you specify a dump class name on installation panel DSNTIP6 or if you specify the DUMPCLASS option on the RECOVER utility statement, then the data sets will be restored from the system-level backup that was dumped to that particular DFSMShsm dump class. If you do not specify a dump class name on installation panel DSNTIP6 or on the RECOVER utility statement, then the RESTORE SYSTEM utility issues the DFSMShsm LIST COPYPOOL command and uses the first dump class listed in the output.

Use the output from LISTCOPY POOL and PRINT LOG MAP to see the system-level backup information.

Use the output from the REPORT RECOVERY utility to determine whether the objects to be recovered have image copies, concurrent copies, or a utility LOG YES event that can be used as a recovery base. You also can determine if these objects are contained in a system-level backup.

You can take system-level backups using the BACKUP SYSTEM utility. However, if any of the following utilities were run since the system-level backup that was chosen as the recovery base, then the use of the system-level backup is prohibited for object level recoveries to a prior point in time:
  • REORG TABLESPACE
  • REORG INDEX
  • REBUILD INDEX
  • LOAD REPLACE
  • RECOVER from image copy or concurrent copy

In the following illustration, RECOVER TOLOGPOINT receives message DSNU1528I with return code 8, indicating that the recovery has failed.

Figure 1. Failed recovery
Begin figure description. This figure is a time line of a failed recovery. End figure description.

In this example, use RECOVER with RESTOREBEFORE X'A0000' to use inline image recovery copy taken at X'90000' as a recovery base.