Recovering with a data set copy that is not made by Db2

You can restore a data set to a point of consistency by using a data set copy that was not made by the COPY utility.

After recovery to the point of consistency, if you choose to continue and recover to the current point in time, you do not want RECOVER to begin processing by restoring the data set from a Db2 image copy. Therefore, use the LOGONLY option of RECOVER, which causes RECOVER to skip the RESTORE phase and apply the log records only, starting from the first log record that was written after the data set was backed up.

Because the data sets are restored offline without Db2 involvement, RECOVER LOGONLY checks that the data set identifiers match those that are in the Db2 catalog. If the identifiers do not match, message DSNU548I is issued, and the job terminates with return code 8.

You can use the LOGONLY option on a list of objects.

To ensure that no other transactions can access Db2 objects between the time that you restore a data set and the time that you run RECOVER LOGONLY, follow these steps:

  1. Stop the Db2 objects that are being recovered by issuing the following command: 
    -STOP DATABASE(database-name) SPACENAM(space-name)
  2. Restore all Db2 data sets that are being recovered.
  3. Start the Db2 objects that are being recovered by issuing the following command: 
    -START DATABASE(database-name) SPACENAM(space-name) ACCESS(UT)
  4. Run the RECOVER utility without the TORBA or TOLOGPOINT parameters and with the LOGONLY parameter to recover the Db2 data sets to the current point in time and to perform forward recovery using Db2 logs. If you want to recover the Db2 data sets to a prior point in time, run the RECOVER utility with either TORBA or TOLOGPOINT, and with the LOGONLY parameters.
  5. If you did not recover related indexes in the same RECOVER control statement, rebuild all indexes on the recovered object.
  6. Issue the following command to allow access to the recovered object if the recovery completes successfully: 
    -START DATABASE(database-name) SPACENAM(space-name) ACCESS(RW)

With the LOGONLY option, when recovering a single piece of a multi-piece linear page set, RECOVER opens the first piece of the page set. If the data set is migrated by DFSMShsm, the data set is recalled by DFSMShsm. Without LOGONLY, no data set recall is requested.

Backing up a single piece of a multi-piece linear page set is not recommended. This action can cause a data integrity problem if the backup is used to restore the data set at a later time.