Doesn't the use of snapshots (and their backup) help with this ? I am assuming here that you mean that the source got corrupted some time after it was created (

Doesn't the use of snapshots (and their backup) help with this ? I am assuming here that you mean that the source got corrupted some time after it was created (and anyway, if it is not the case, it is a issue unrelated to backup, in my opinion). A proper backup tool should help you keep several versions of your data without using a proportional amount of space, by using some form of deduplication. I use borg backup for my backup, and I can go back to any day in the past three years and get an old copy of any document (as long as I saved it on my disk for more than one day, since I do daily backups) You can also setup "append only" backups, if you are worried that somebody may willingly try to destroy your old copies