CloudBacko Upgrade Advisory (#33940) - Data corruption issue on any backup types for Backup Sets upgraded to v5 (pre-v5.1.4.0) from v4 or earlier Backup Sets

Posted: 2022-05-05

This advisory affects any legacy customer with CloudBacko v4 or earlier Backup Sets, who upgrade to CloudBacko v5.1.0.x, new data backed up since v5 is unrestorable. On the other hand, this will not affect you if you are new to CloudBacko v5.1 or created new v5 Backup Sets.

We have recently identified and confirmed a critical bug found in CloudBacko v5 Pro/Home/Lite (pre-v5.1.4.0) that affects all types of Backup Sets, where v5 data is unrestorable (restoring data from time period prior to v5 backup dates, is restorable).

Backup users who have Backup Sets created from CloudBacko v4 or earlier, who upgrade to v5 are affected under certain conditions:

  v4 data + v5 data on Pro/Home/Lite v5.1.0.0 to v5.1.0.x
  source files greater than 32MB
  Deduplication Migrate Data option = DISABLED
  ==> affected. Probability for data corruption for data backed up between v5.1.0.0 to v5.1.0.x

  v4 data + v5 data on Pro/Home/Lite v5.1.0.0 to v5.1.0.x
  source files greater than 32MB
  Deduplication Migrate Data option = ENABLED
  => not affected.

  v4 data + v5 data on Pro/Home/Lite v5.1.0.0 to v5.1.0.x
  source files less than 32MB
  Deduplication Migrate Data option = DISABLED
  => not affected.

  v4 data + v5 data on Pro/Home/Lite v5.1.0.0 to v5.1.0.x
  source files less than 32MB
  Deduplication Migrate Data option = ENABLED
  => not affected.

  new v5 backup set on Pro/Home/Lite v5.x
  => not affected.

• On Backup Sets containing both v4 Data + v5 Data, the probability for data corruption (unrestorable data) affecting the v5 data backed up between v5.1.0.0 up to v5.1.0.x, where Deduplication Migrate Data option = DISABLED and source file is >32MB.

• After upgrading to v5, an internal transition (migrated) table needs to track data existing in pre-v5 backup and reference with data being backed up by v5. The migrate status wasn't correctly tracked for each backup file; causing the backup file to still refer to the legacy [pre-v5 data] instead of the hybrid [v5-data + pre-v5 data].

• Pro/Home/Lite v5.1.0.0 to v5.1.0.x

• Yes, if this is true:

  v4 data + v5 data on Pro/Home/Lite v5.1.0.0 to v5.1.0.x
  source files greater than 32MB
  Deduplication Migrate Data option = DISABLED
  ==> affected. Probability for data corruption for data backed up between v5.1.0.0 to v5.1.0.x

• This will only help for data backed up after setting is ENABLED, any v5 backup data prior to enabling this feature should be considered corrupt.
• If this setting is later changed to DISABLED, then consider those v5 backup data after the change, corrupt; until the setting is ENABLED and jobs run.

• It is not affected. These source data isn't chunked for Deduplication.

• It depends on the conditions stated above.

• Take immediate action to download and install latest release of CloudBacko v5.1.4.0.
• Once required minimum hotfix version is applied, the next backup job will automatically first run a PDIC to handle (remove) corrupted backup file, then reupload source backup file that was corrupted and correctly update the migrate status table.

• Stop! Do not upgrade until you contact a member our Sales team for assistance with your License upgrade.