I am in a chicken-egg situation for my secondary harddrive (non boot):
- My BTRFS mount has gone readonly because no space left.
btrfs filesystem resize
only works on mounted volumes.- I needed to umount this ro mount in force mode (because of device busy).
- If I try to mount rw it fails because of errors (most likely caused by no space left)
- If I try to run
btrfs check --repair
it gives device busy
What to do to find out what keeps /dev/sda
busy? My hdd is listed in /etc/fstab
, does that matter (UUID=262a8d86-279a-4f6b-8968-32e200c32255 /mnt/hdd btrfs defaults,compress=zlib 0 1
)???
I tried:
lsof | grep /dev/s
-> nothinglsof | grep /mnt/hdd
-> nothing- The same for
fuser
-> nothing
So:
mount -o recovery /dev/sda /mnt/hdd
[63035.539792] BTRFS error (device sda): Remounting read-write after
error is not allowed
If I try to run:
root@myhost:/mnt# btrfs check --repair /dev/sda
enabling repair mode
ERROR: cannot open device '/dev/sda': Device or resource busy
ERROR: cannot open file system
Best Answer
from https://btrfs.wiki.kernel.org/index.php/Btrfsck It is highly recommended to get the latest version of btrfs-tools and recover important data with:
before you: btrfs check --repair
Mounting ro is whats recommended.