- You create a plan to backup disks/partitions with the following parameters:
- Backup format: Version 12 (.tibx)
- Where to backup: internal or external disk
- Backup scheme: full backup + differential backups
- Cleanup: by number of backups (e.g. maximum number of backups= 3)
- You run the backup task several times;
- TIBX files from differential backups do not get deleted from storage, even if number of .TIBX files exceeds the specified maximum number of backups. Product GUI shows the number of recovery points according to retention rules, however the backup location contains more .TIBX files.
Specifics of product design.
Unlike Version 11 format that performed hard consolidation of backup archives, Version 12 only relinks data in the scenario when backups would be consolidated. Thus, when using Version 12 backup format, if you attempt to delete a full backup before its dependent differential, their data gets "linked" together, as a result having one logical backup in the GUI but leaving .TIBX files in place physically.
To work around this limitation you need to delete Differential backups before the Full backup that they depend on. To do it choose cleanup By backup age and select required time for each backup set: