Backup consolidation

This option defines whether to consolidate backups during cleanup or to delete entire backup chains.

The preset is: Disabled.

Consolidation is the process of combining two or more subsequent backups into a single backup.

If this option is enabled, a backup that should be deleted during cleanup is consolidated with the next dependent backup (incremental or differential).

Otherwise, the backup is retained until all dependent backups become subject to deletion. This helps avoid the potentially time-consuming consolidation, but requires extra space for storing backups whose deletion is postponed. The backups' age or number can exceed the values specified in the retention rules.

Please be aware that consolidation is just a method of deletion, but not an alternative to deletion. The resulting backup will not contain data that was present in the deleted backup and was absent from the retained incremental or differential backup.

This option is not effective if any of the following is true:

  • The backup destination is a tape device or the cloud storage.
  • The backup scheme is set to Always incremental (single-file).
  • The backup format is set to Version 12.

Backups stored on tapes cannot be consolidated. Backups stored in the cloud storage, as well as single-file backups (both version 11 and 12 formats), are always consolidated because their inner structure makes for fast and easy consolidation.

However, if version 12 format is used, and multiple backup chains are present (every chain being stored in a separate .tibx file), consolidation works only within the last chain. Any other chain is deleted as a whole, except for the first one, which is shrunk to the minimum size to keep the meta information (~12 KB). This meta information is required to ensure the data consistency during simultaneous read and write operations. The backups included in these chains disappear from the GUI as soon as the retention rule is applied, although they physically exist until the entire chain is deleted.

In all other cases, backups whose deletion is postponed are marked with the trash can icon () in the GUI. If you delete such a backup by clicking the X sign, consolidation will be performed. Backups stored on a tape disappear from the GUI only when the tape is overwritten or erased.