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Combination of rules 1 and 2
You can limit both the backups’ lifetime and the archive size. The diagram below illustrates the
resulting rule.
Example
Delete backups older than = 3 Months
Keep the archive size within = 200GB
Never delete backups younger than = 10 Days
Every time the retention rules are applied, the program will delete all backups created more than
3 months (or more exactly, 90 days) ago.
If after the deletion the archive size is more than 200GB, and the oldest backup is older than 10
days, the program will delete that backup.
Then, if necessary, the next old backup will be deleted, until the archive size decreases to the
preset limit or the oldest backup age reaches 10 days.
Deleting backups with dependencies
Both retention rules presume deleting some backups while retaining the others. What if the archive
contains incremental and differential backups that depend on each other and on the full backups
they are based on? You cannot, say, delete an outdated full backup and keep its incremental
“children”.
When deletion of a backup affects other backups, one of the following rules is applied:
Retain the backup until all dependent backups become subject to deletion
The outdated backup will be kept until all backups that depend on it also become outdated. Then
all the chain will be deleted at once during the regular cleanup. This mode helps to avoid the
potentially time-consuming consolidation but requires extra space for storing backups whose
deletion is postponed. The archive size and/or the backup age can exceed the values you specify.
Consolidate the backup
The program will consolidate the backup that is subject to deletion with the next dependent
backup. For example, the retention rules require to delete a full backup but retain the next
incremental one. The backups will be combined into a single full backup which will be dated the
incremental backup date. When an incremental or differential backup from the middle of the
chain is deleted, the resulting backup type will be incremental.
This mode ensures that after each cleanup the archive size and the backups’ age are within the
bounds you specify. The consolidation, however, may take a lot of time and system resources.
And you still need some extra space in the vault for temporary files created during consolidation.
What you need to know about consolidation