CloudBacko Upgrade Advisory (#34490) - Data corruption issue on any v5.1.4.0 to v5.1.4.21 backup types

Posted: 2022-06-02 Revised: 2022-07-11

We have recently identified and confirmed a critical bug found in CloudBacko Pro / Lite / Home (v5.1.4.0 to v5.1.4.21) that affects all types of Backup Sets, where source backup data is >32MB, resulting in unrestorable v5.1.4.x data.

Not affected is restoring data from time period prior to v5.1.4.0 backup dates (ie v5.1.0.0 data is not affected).

• UPDATE: On 2022-July-11 CloudBacko v5.3.2.0 is released; upgrade to this latest release to fix the issue.

• Affecting CloudBacko v5.1.4.0 up to v5.1.4.21 , for ANY Backup Set types where source files have raw size greater-than 32MB, and Deduplication = OFF.
• Example, “tasks.zip” is 40MB, is affected.
• Example, “mylist.txt” is 2MB, is not affected.

• This happens in lookup (find duplicated data) logic in backup of all Backup Set types, when Deduplication is OFF.
• v5.1.4.0 to v5.1.4.21 will always find duplicated data from index even Deduplication is OFF. The lookup result will be wrong, hence, the file data is already corrupt.

• Unable to restore due to corrupt backup data

• CloudBacko v5.1.4.0 up to v5.1.4.21 , where Deduplication = OFF at any point during backup runs within these versions
• CloudBacko v5.1.4.0 up to v5.1.4.21 , where Deduplication = ON and Migrate Data = ENABLED (checkbox marked)
• CloudBacko v5.1.4.0 up to v5.1.4.21 , where Deduplication = ON and Migrate Data = DISABLED (checkbox unmarked)
• [Updated: 2022-06-22] Additional analysis has shown that Backup Sets where Deduplication = ON (Enabled) , are not affected by this corruption.

• By default, Deduplication is ON (enabled), both module and Backup Set.
• It will be OFF (disabled) if Deduplication toggle is OFF manually per Backup Set
• Above are sample default behavior, as there can be other contributing factors that may affect settings, you should review your settings to verify behavior in your environment.

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

• It depends on the conditions stated above.

• No workaround. Data must be backup again after fix is applied.

• Take immediate action to download and install latest hotfix v5.1.4.22 (or higher) via CloudBacko website (https://www.cloudbacko.com/cloudbacko-support).
  • UPDATE: On 2022-July-11 we released CloudBacko v5.3.2.0; it is recommended to upgrade to this latest release as it includes prior hotfixes. Hotfixes for v5.1.4.x is no longer available.
• Once required minimum hotfix version is applied, as a one-time routine the next backup job will automatically remove Blocks (BAK) from the Destination containing backup files that reference invalid checksum file chunks, then reupload source backup file that was corrupted and correctly update the migrate status table. A flag will be set in the Index to denote fix was applied ( likewise reverting the Index to an older copy will retrigger the fix ). [Shared Blocks (BAK), a block containing multiple small source files (valid and corrupt), won't be purged until all contents of shared block has cycled through changes and surpass Retention period.]

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