I’m trying to plan a better backup solution for my home server. Right now I’m using Duplicati to back up my 3 external drives, but the backup is staying on-site and on the same kind of media as the original. So, what does your backup setup and workflow look like? Discs at a friend’s house? Cloud backup at a commercial provider? Magnetic tape in an underground bunker?
Hm I wonder why snapshots wouldn’t satisfy 3. Copies on the same disk like /file, /backup1/file, /backup2/file should satisfy 3. Why wouldn’t snapshots be equivalent if 3 doesn’t guard against filesystem or hardware failure? Just thinking and curious to see opinion.
If I’m reading your example right, I don’t think that would satisfy three either. Three copies of the data on the same filesystem or even the same system doesn’t satisfy the “three backups” rule. Because the only thing you’re really protecting against is maybe user error. I.e. accidental deletion or modification. You’re not protecting against filesystem corruption or system failure.
For a (little bit hyperbolic) example, if you put the system that has your live data on it through a wood chipper, could you use one of the other copies to recover your critical data? If yes, it counts. If no, it doesn’t.
Snapshots have the same issue, because at the root a snapshot is just an additional copy of the data. There’s additional automation, deduplication, and other features baked into the snapshot process but it’s basically just a fancy copy function.
Edit: all of the above is also why the saying “RAID is not a backup” holds true.
Right so I guess the question of 3 is whether it means 3 backups or 3 copies. If we take it literally - 3 copies, then it does protect from user error only. If 3 backups, it protects against hardware failure too.
E: Seagate calls them copies and explicitly says the implementer can choose how the copies are distributed across the 2 media. The woodchipper scenario would be handled by the 2 media requirement.