On Wed, Dec 18, 2013 at 11:05:29AM +0000, Hugo Mills wrote: > On Wed, Dec 18, 2013 at 10:44:43AM +0000, Leonidas Spyropoulos wrote: > > I'm using the same subject as it might be relevant, feel free to change it.# > > > > I'm trying to do some maintenance to the system running over a btrfs file system on root (/). I started a balance on the '/' partition and it failed with the below information: > > $ sudo btrfs balance start / > > [sudo] password for inglor: > > ERROR: error during balancing '/' - No space left on device > > There may be more info in syslog - try dmesg | tail > > $ dmesg | tail > > [93827.115887] btrfs: found 29461 extents > > [93827.481849] btrfs: relocating block group 29855055872 flags 1 > > [93841.646011] btrfs: found 33171 extents > > [93851.421207] btrfs: found 33171 extents > > [93851.782054] btrfs: relocating block group 28781314048 flags 1 > > [93866.815342] btrfs: found 52535 extents > > [93877.159354] btrfs: found 52534 extents > > [93877.356805] btrfs: relocating block group 28747759616 flags 34 > > [93880.287185] btrfs: found 1 extents > > [93880.608798] btrfs: 1 enospc errors during balance > > You don't specify your kernel version, but if it's older than 3.11 > or so, you should probably upgrade -- 3.10 and earlier had occasional > bugs where the block reserve system never kept enough blocks free to > add a new metadata chunk when it was needed, which led to exactly this > kind of symptom. You are right, apologies. It is an up to date Archlinux box with a kernel: $ uname -a Linux tiamat 3.12.5-1-ARCH #1 SMP PREEMPT Thu Dec 12 12:57:31 CET 2013 x86_64 GNU/Linux > > Alternatively, and this is a bit of a long shot given that the > error seems to have been while relocating your system chunk (which > argues against this particular diagnosis), but: > > Do you have a large file on that filesystem (larger than 1 GiB)? Unlikely since the btrfs file system in question is '/' exluding /opt and /media directories (these are other partitions) $ sudo find / -type f -size +1048576k -and -not -path "/media*" -print /proc/kcore find: `/proc/27221/task/27221/fd/5': No such file or directory find: `/proc/27221/task/27221/fdinfo/5': No such file or directory find: `/proc/27221/fd/5': No such file or directory find: `/proc/27221/fdinfo/5': No such file or directory find: `/run/user/1000/gvfs': Permission denied inglor@tiamat ~$ > > If so, I would recommend switching to a 3.12 kernel, and running a > defrag on the file. There's a known and now-fixed bug where you can > get ENOSPC while balancing, if a file has an extent larger than 1 GiB > in size. (The bug being that there's an extent over 1 GiB in size in > the first place). I might try the defrag option anyway and restart the balance operation, see if this will help anyway. Thanks, Leonidas > > Hugo. > > -- > === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === > PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk > --- I'd make a joke about UDP, but I don't know if --- > anyone's actually listening... -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html