I've been using btrfs for a couple of years now and it has saved my ass on a couple of occasions - this weekend again.
I'm periodically doing a
on all hard drives. What btrfs scrub does: It validates all checkssums on the given filesystem, so you can see if one (or more than one) file have succumbd to bit rot
. Guess what?
scrub device /dev/mapper/crbackup (id 1) history
Scrub started: Sat Feb 1 00:00:09 2020
Total to scrub: 1.63TiB
Error summary: csum=256
Fortunately the files in question are rather unimportant backups:
[1061203.625001] BTRFS warning (device dm-3): checksum error at logical 22266249216 on dev /dev/mapper/crbackup, physical 23348379648, root 14466, inode 6257873, offset 71372800, length 4096, links 1 (path: email@example.com)
If I'd sill using old-fashioned filesystems like ext4 I wouldn't have noticed