btrfs on openSUSE not releasing disk space

Question

I have an openSUSE 12.1 install on my main desktop running with btrfs filesystem for root (/boot is ext4). I started having issues today with KDE informing me that disk space is almost all gone and eventually it decided it was gone and crashed my desktop.

I used Alt+F1 to switch to a terminal screen and although I was sure I was no where near the 1TB limit of my hard disk I moved some 150/200GB of music and video files onto an external drive and rebooted. Didn't help, same problem, same crash.

Once more I switched to a terminal screen and used du to confirm that I had indeed only used about half of my total diskspace but df (including the btrfs-progs version) insists I have used 100% of available diskspace and so my desktop crashes each and every time I log in.

Using the btrfs defrag utility doesn't help either. As such I am at a bit of a loss as to where to go next.

Answer 1

openSUSE 12.1, if installed on btrfs, automatically enables tool called snapper which uses btrfs snapshotting to get snapshots of the system before installing new packages. It is well possible that these snapshots are consuming your disk space. Check out your snapshots with snapper list command.

Snapshots can be configured using /etc/snapper/configs/root (see man 5 snapper-configs for details).

You can list existing snapshots using snapper -c root list, and you can force removing older snapshots by:

• snapper -c root cleanup timeline
• snapper -c root cleanup number

See man 8 snapper for details. Check out this blogpost for more information about btrfs/snapper/opensuse 12.1.

Answer 2

Eventually my system would no longer boot even to single user mode after attempting to fix so have re-installed.