Re: Unexpected ENOSPC on a SSD-drive after day of uptime, kernel 2.6.32-rc5

[Josef Bacik <josef@redhat.com>]

On Thu, Nov 05, 2009 at 08:38:18PM +0000, miyamoto moesasji wrote:
> I've just finished installing onto an OCZ Agilent v2 SSD with btrfs as
> filesystem. However to my surprise I've hit an ENOSPC condition one
> one of the partitions within less than a day of uptime, while the
> filesystem on that partition only reported 50% to be in use, which is
> far from the 75% limit people mention on the ML.
> 
> Note that this occurs using a vanilla 2.6.32-rc5 kernel on a 64-bit
> gentoo system.
> 
> Error-message from logs:
> 
> 2009-11-05T07:55:57.586574+00:00 PulsarX4 kernel: [  136.095961] no
> space left, need 4096, 4440064 delalloc bytes, 10704142336 bytes_used,
> 0 bytes_reserved, 0 bytes_pinned, 0 bytes_readonly, 0 may use
> 10708582400 total
> 2009-11-05T07:55:57.645314+00:00 PulsarX4 kernel: [  136.154217] no
> space left, need 4096, 4448256 delalloc bytes, 10704134144 bytes_used,
> 0 bytes_reserved, 0 bytes_pinned, 0 bytes_readonly, 0 may use
> 10708582400 total
> 
> Further details:
> 
> 0) The partition that reports ENOSPC is mounted as:
> /dev/sda3		/usr			btrfs		defaults,rw,nodev,noatime					
> 
> 1) df -h reports : /dev/sda3              21G   11G  9.5G  53% /usr
> 
> 2) btrfs-show :
> Label: none  uuid: 0a89100d-096d-4c67-b3c7-745c9b7c3dc5
> 	Total devices 1 FS bytes used 10.60GB
> 	devid    1 size 20.00GB used 20.00GB path /dev/sda3
> 
> 3) The other partitions using btrfs show a similar relatively large
> difference between the space reported by df -h and the size being
> taken up according to btrfs-show.
> 
> Although this potentially is a problem between screen and chair I
> don't see what I am doing wrong. Note that the ENOSPC issue occurs on
> a partition that still allows me to boot, so it is possible to run
> tests if needed when this indeed turns out to be a bug.
> 
> Please let me know in case I need to provide further details from the logs.

Hmm looks like quite a bit of your fs got taken up for metadata.  Perhaps try
running btrfsctl -b /usr and see if that frees up some space for you.  Thanks,

Josef