Diagnosing why a backup failed verification

If a backup failed verification, you can take steps to diagnose and attempt to fix the problem.

1. Verify that the AC_CONFIG environment variable and the contents of the archecker configuration file are set correctly. If these variables are set incorrectly, the ON-Bar activity log prints a message.
2. Back up the data onto different media.

   Do not reuse the original backup media because it might be damaged.

   Do not use any backups based on this backup. If the level-0 backup failed verification, do not use the corresponding level-1 and level-2 backups.

3. Verify this new backup. If verification succeeds, you can restore the storage spaces.
4. Use your storage manager to expire the backup that failed verification and then run the onsmsync utility without arguments to remove the bad backup from the sysutils and emergency boot files.
5. If verification fails again, call IBM® Software Support and provide them with the following information:
   • Your backup tool name (ON-Bar)
   • The database server online.log
   • The archecker message log
   • The AC_STORAGE directory that contains the bitmap of the backup and copies of important backed-up pages

   If only part of the backup is corrupted, IBM Software Support can help you determine which portion of the backup can be restored in an emergency.

   IBM Software Support might advise you to run oncheck options against a set of tables.