Another data corruption, fortunately not fatal, with btrfs. Two mirrored disks that have little activity. On the same server, Proxmox 9, there is also a ZFS pool (mirrored, more active). Same type of disks.
An employee mistakenly connected an electric heater to a socket protected by the UPS, and the server rebooted brutally.
Upon reboot, one of the two btrfs disks reported:
[ 167.015266] BTRFS error (device sdd): parent transid verify failed on 873906176 wanted 998679 found 998677
[ 167.017007] BTRFS error (device sdd): parent transid verify failed on 873906176 wanted 998679 found 998677
[ 167.052517] BTRFS error (device sdd): open_ctree failed mount: /btrfs: can't read superblock on /dev/sdd.
Result: unable to mount, even in degraded mode. The only way was to disconnect sdd and mount the other disk in degraded mode.
No issues with the ZFS pool.
Needless to say, I'm now copying the data to ZFS, and before tomorrow, these two disks will be a new ZFS pool.