On Sun, Sep 3, 2017 at 11:19 PM, Russell Coker <russell+btrfs@xxxxxxxxxxxx> wrote: > I have a system with less than 50% disk space used. It just started rejecting > writes due to lack of disk space. What's the error? Is it ENOSPC? Kinda needs kernel messages, and also if it's ENOSPC to have mounted with enospc_debug option. Also everytime this has come up before, devs have asked for $ grep -R . /sys/fs/btrfs/fsuuid/allocation/ I have no idea how to parse that myself, but there is probably a way to anticipate enoscp from that information if you can learn how to parse it. > I ran "btrfs balance" and then it started > working correctly again. It seems that a btrfs filesystem if left alone will > eventually get fragmented enough that it rejects writes (I've had similar > issues with other systems running BTRFS with other kernel versions). > > Is this a known issue? Sounds like old thread "BTRFS constantly reports "No space left on device" even with a huge unallocated space" but that's a long time ago, and kernel ~4.7.3 fixed it. Whatever that was should be in 4.9.30. Another possibility is there's a small bug in some cases where things go around the new ticketed enospc infrastructure, and that was fixed in 4.9.42 and 4.12.6. So you should try one of those and see if it fixes the problem. -- Chris Murphy -- 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
