Retention rules allow you to limit the backup archive size and set the lifetime for backups. This way you can ensure that backups do not fill up all the available storage space.
The following retention rules can be specified:
- Delete backups older than: when retention rules are applied, the program deletes all archives older than the specified age;
- Delete backups when the number of backups exceeds: the program deletes the archives when their quantity comes a specified predetermined number.
Select the Automatically delete old backups check box to define the cleanup rules for backup management inside the archive - simple cleanup scheme or “Grandfather-Father-Son” cleanup scheme. Simple cleanup schemeallows you to keep a pre-defined number of the backups inside the archive or keep the backups for some pre-defined period. GFS cleanup scheme allows you to keep a pre-defined number of daily, weekly and monthly backups. All backups made within one day are considered to be “daily” ones and will be all deleted when that date becomes expired. The same concept applies to “weekly” backups.
All retention rules are applied before and after the backup task execution. Note that at least one backup will always remain intact inside the archive even if this backup becomes a subject to deletion according to the specified retention rules. This design ensures that you always have at least one backup available for recovery in the archive. This will be true until you clear the Never delete the last remaining backup check box (selected by default) which defines the behavior of the program when there is only one valid recovery point left and it becomes a subject to deletion. This may be the case, for example, when you have applied a backup task to some group of virtual machines and one of these machines has been deleted from the ESX(i) host making it no longer possible to be backed up. At some point (according to the specified retention rules), all the backups of this deleted VM will become subject to deletion. Accordingly, the Never delete the last remaining backup check box will prevent or force the deletion of the last remaining backup.