Extended use of snapshots

[Adequat]

The basic concept is to prevent this scenario: to have a backup disk updated everyday and containing a file with a defect (eg. bad disk sector occuring after the file was backup), and not being able to know about it.

Consider the following case:

There is an external drive used for backup, which is the mirror of another working drive. Everyday, the backup drive is updated from the working drive changes. I would like a snapshot (with CRC) of the backup disk to be updated (not recreated) after each synchronization. In this way, it is possible to verify the integrity of the backup disk, manually, at any desired time.