When the data lifecycle manager (DLM) process encounters an invalid database entry, it may delete deduplication disk storage or a disk storage (disk-based backup folders) from the disk. DLM does this when it attempts to delete expired backup sets.
For deduplication disk storage, first the Backup Exec Deduplication Engine and Manager Services fail to load, and then the deduplication disk storage appears as offline in the user interface. The files for the deduplication disk storage device are also deleted from disk.
This issue can also happen with a disk storage. Currerntly. Symantec is only aware of incidents that have affected deduplication disk storage.
During failed backup operations for which the Granular Recovery Technology (GRT) option is enabled, the Backup Exec database gets the wrong path for a backup set. The path points to the top level of the storage device. When the backup set is scheduled for expiration, the data lifecycle manager process deletes the directory that is referred to in the database entry.
Symantec recommends that you immediately apply Hotfix 200433 to all installations of Backup Exec 2012 before this issue occurs. If you wait until after deduplication storage or disk storage has been deleted, there are limited options. For deduplication disk storage, the interconnections between the various components make it unlikely that any data can be restored from the disk, even if you ues third-party disk recovery techniques. For disk storage, it is possible that you can use third-party disk recovery techniques to restore intact data sets, but even this is dependent on the size of the data removed, the time between the occurrence and detection of the problem, and the amount of new data that was written to the volume in the intervening time.
This issue is resolved in Hotfix 200433 for Backup Exec 2012 SP1 (TECH200433).
This issue can occur on Backup Exec 2012 environments using Deduplication or Backup-to-Disk storage for GRT backups, in which Hotfix 200433 has not been installed.