Synology BTRFS repair

Repair synology BTRFS volume

btrfs fi show -d
(/dev/mapper/vg1000-lv)

syno_poweroff_task -d

(or: umount /volume1)
(or2: umount /volume1 -f -k)

Check to see if all us unmounted:
df -h

mdadm --stop /dev/vg1000/lv

btrfsck /dev/vg1000/lv

btrfs check --repair /dev/vg1000/lv

btrfs rescue super-recover -v /dev/vg1000/lv

vgchange -ay

e2fsck -nvf -C 0 /dev/vg1000/lv

fsck.ext4 -pvf -C 0 /dev/vg1000/lv

(or: e2fsck -pvf -C 0 /dev/vg1000/lv -C O)
(do not do this: -C fd)

@eduarcor do you have snapshots enabled on those two files? Might be that the snapshots are interfering?

I don’t have any snapshot. I am not using snapshots

With DSM 7.2.2-72806 Update 3:

# to unmount
synostgvolume --unmount -p /volume1

# to mount the logic volume (I read it somewhere...)
vgchange -ay

# to just check
btrfs check /dev/mapper/cachedev_0

# to enable repair
btrfs check --clear-space-cache v2 /dev/mapper/cachedev_0

# to repair and pray
btrfs check --repair /dev/mapper/cachedev_0

P.S.: there are problems that can't be repaired. Then you should backup (before trying to repair), remove the volume and start again.