The backup database is in error, the primary database is unaffected

In this situation, follow this procedure:

Issue RVARY INACTIVE for the backup.
Take one of the following actions:
1. Correct the problem on the backup, using BLKUPD.
2. If the device is accessible, copy the primary onto the backup, using IRRUT200 with PARM=ACTIVATE or IRRUT400.
3. If the device is inaccessible, allocate, catalog, and copy a replacement backup onto a different DASD device, using IRRUT200 or IRRUT400.
If you used IRRUT400, or IRRUT200 without PARM=ACTIVATE in option 2.b, issue RVARY ACTIVE for the backup. If you used IRRUT200 with PARM=ACTIVATE, the backup is already active.
If you used option 2.b with IRRUT400 with LOCKINPUT, run IRRUT400 with UNLOCKINPUT to unlock your new primary (original backup).

Note: To minimize the possibility of your primary and backup databases getting out of synch, the safest approach is to use option 2.b with IRRUT400 and LOCKINPUT or IRRUT200 with PARM=ACTIVATE.