[opensuse-kernel] btrfs crash at 97% space usage
Hi: In current kernel HEAD I have a btrfs crash on a filesystem that is 97% full.. While I was able to dmesg > crash with no error before the machine locked up and becomes unusable (CPU rages fan to full speed, freezes or causes a thermal shutdown) for some reason the "crash" file supposed to be written is not there anymore after reboot, I will try sending the output to a different device the next time it happens, but I wonder if you have any other suggestion how to debug the problem without a serial console. -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2014-01-05 17:24, Cristian Rodríguez wrote:
Hi:
In current kernel HEAD I have a btrfs crash on a filesystem that is 97% full..
That is perhaps similar to the problem I demonstrated by filling the partition up. There is a bugzilla about that since 13.1 RCx. - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlLJn8cACgkQtTMYHG2NR9WxRQCdG3tIO/APt5K2X8ESrElmOLn7 ibsAnA+Wb9CMWCvKzGizaWt9fFTQwXzQ =hpdJ -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org
On 1/5/14, 1:09 PM, Carlos E. R. wrote:
On 2014-01-05 17:24, Cristian Rodríguez wrote:
Hi:
In current kernel HEAD I have a btrfs crash on a filesystem that is 97% full..
That is perhaps similar to the problem I demonstrated by filling the partition up. There is a bugzilla about that since 13.1 RCx.
It might be. The problem here is not as simple as it may seem from the outset. We're able to reproduce it easily and Mark is working on a fix. The short version is that once an extent is allocated, *all* of the blocks within the extent need to be released before the extent is released. On a CoW file system with a lot of potential fragmentation, this can end up resulting in a lot of space accounted for as freed but not actually available for allocation. What needs to happen is that we need to break apart the extents when blocks are released. Unfortunately, that requires a disk format change since earlier releases won't do it. Disk format changes can take a while do get done. -Jeff -- Jeff Mahoney SUSE Labs
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2014-01-17 18:42, Jeff Mahoney wrote:
On 1/5/14, 1:09 PM, Carlos E. R. wrote:
On 2014-01-05 17:24, Cristian Rodríguez wrote:
Hi:
In current kernel HEAD I have a btrfs crash on a filesystem that is 97% full..
That is perhaps similar to the problem I demonstrated by filling the partition up. There is a bugzilla about that since 13.1 RCx.
It might be. The problem here is not as simple as it may seem from the outset. We're able to reproduce it easily and Mark is working on a fix.
The short version is that once an extent is allocated, *all* of the blocks within the extent need to be released before the extent is released. On a CoW file system with a lot of potential fragmentation, this can end up resulting in a lot of space accounted for as freed but not actually available for allocation. What needs to happen is that we need to break apart the extents when blocks are released. Unfortunately, that requires a disk format change since earlier releases won't do it. Disk format changes can take a while do get done.
Thanks for the explanation. Short story: it is complicated. :-} - -- Cheers / Saludos, Carlos E. R. (from 12.3 x86_64 "Dartmouth" at Telcontar) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlLZvqsACgkQtTMYHG2NR9Vm4wCeKJFIWrpFGK2jY8/jjXkUVksq AuAAoI3tGzPulunwAFPlW7lwDXCZryXT =5d2p -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org
El 17/01/14 14:42, Jeff Mahoney escribió:
On 1/5/14, 1:09 PM, Carlos E. R. wrote:
On 2014-01-05 17:24, Cristian Rodríguez wrote:
Hi:
In current kernel HEAD I have a btrfs crash on a filesystem that is 97% full..
That is perhaps similar to the problem I demonstrated by filling the partition up. There is a bugzilla about that since 13.1 RCx.
It might be. The problem here is not as simple as it may seem from the outset. We're able to reproduce it easily and Mark is working on a fix.
Since I freed some space in the FS I have not been able to reproduce it, however it will soon reach the same percentage again and we will see if it happens again. :-) -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org
participants (3)
-
Carlos E. R. -
Cristian Rodríguez -
Jeff Mahoney