The two main reasons I can think of for taking backups seems to be taken care of when I use both snapshots and RAID together with btrfs. (By RAID here, I mean RAID1 or 10)
- Accidental deletion of data: Snapshots covers this case
- Failure of a drive and bit rot
- Complete failure: RAID covers this case
- Drive returning bad data: RAID + btrfs' error correcting feature covers this case
So as an on-site backup solution, this seems to work fine, and it doesn't even need a separate data storage device for it!
However, I have heard that both RAID and snapshots aren't considered proper backups, so I'm wondering if I have missed anything.
Aside from btrfs not being a mature technology yet, can you think of anything I've missed? Or is my thinking correct and this is a valid on-site backup solution?