RESTORE SYSTEM

The RESTORE SYSTEM online utility invokes z/OS® DFSMShsm to recover a DB2® subsystem or a data sharing group to a previous point in time. To perform the recovery, the utility uses data that is copied by the BACKUP SYSTEM utility.

Requirements:
  • All data sets that are recovered with RESTORE SYSTEM must be SMS-managed.
  • In general, RESTORE SYSTEM requires z/OS DFSMShsm Version 1 Release 7 or later.
  • RESTORE SYSTEM requires z/OS DFSMShsm Version 1 Release 8 or later for restoring system-level backups that have been dumped to tape.

The RESTORE SYSTEM utility can be run from any member in a data sharing group, even one that is normally quiesced when any backups are taken. Any member in the data sharing group that is active at or beyond the log truncation point must be restarted, and its logs are truncated to the SYSPITR LRSN point.

You can specify the SYSPITR LRSN point in the CRESTART control statement of the DSNJU003 (Change Log Inventory) utility. Any data sharing group member that is normally quiesced at the time the backups are taken and is not active at or beyond the log truncation point does not need to be restarted.

By default, RESTORE SYSTEM recovers the data from the database copy pool during the RESTORE phase and then applies logs to the point in time at which the existing logs were truncated during the LOGAPPLY phase. The RESTORE utility never restores logs from the log copy pool.

Restriction: RESTORE SYSTEM does not restore logs; the utility only applies the logs. If you specified BACKUP SYSTEM FULL to create copies of both the data and the logs, you can restore the logs by another method.

Output:

Output for RESTORE SYSTEM is the recovered copy of the data volume or volumes.

Authorization required

To run this utility, you must use a privilege set that includes SYSADM authority.

Start of changeThe user who submits the job must also have certain RACF® authorities if both of the following conditions are true:End of change

  • A system-level backup on tape is the input for the RESTORE SYSTEM utility.
  • Start of changeThe z/OS level is Version 1 Release 11 or earlier.End of change

In this situation, the following two RACF authorities are required:

  • Operations authority, as in ATTRIBUTES=OPERATIONS
  • DASDVOL authority, which you can set in the following way:
    SETROPTS GENERIC(DASDVOL)
REDEFINE DASDVOL * UACC(ALTER)
SETROPTS CLASSACT(DASDVOL)
SETROPTS GENERIC(DASDVOL) REFRESH
    You can restrict this authority to specific user IDs.

Start of changeThis RACF authority is required, because the RESTORE SYSTEM utility invokes DFSMSdss when tape is the input and the z/OS level is Version 1 Release 11 or earlier. However, DFSMSdss is not invoked when you restore database copy pools from tape when the z/OS level is Version 1 Release 12 or later or from a FlashCopy® on disk. In these situations, the RESTORE SYSTEM utility invokes DFSMShsm, which does not require Operations or DASDVOL authority.End of change

Execution phases of RESTORE SYSTEM

The RESTORE SYSTEM utility operates in the following phases:

Phase
Description
UTILINIT
Performs initialization and setup
RESTORE
Locates and restores the volume copies if the LOGONLY option is not specified
LOGAPPLY
Applies the outstanding log changes to the database
UTILTERM
Performs cleanup