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[Launchpad Bug Tracker <1241848@xxxxxxxxxxxxxxxxxx>]

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I have a Ubuntu 12.04 virtual machine with a 400 GB volume attached to
it. This volume uses XFS filesystem on top of LVM2 setup and the backup
system we use takes hourly backups. Since we freeze and unfreeze the
filesystem during backups, I started seeing the following in the logs a
lot.

Oct 14 06:52:35 localhost kernel: [4269962.940638] XFS (dm-1): xlog_space_left: head behind tail
Oct 14 06:52:35 localhost kernel: [4269962.940639]   tail_cycle = 7, tail_bytes = 38953984
Oct 14 06:52:35 localhost kernel: [4269962.940640]   GH   cycle = 7, GH   bytes = 38953976
Oct 14 06:52:35 localhost kernel: [4269962.940656] XFS (dm-1): xlog_space_left: head behind tail
Oct 14 06:52:35 localhost kernel: [4269962.940657]   tail_cycle = 7, tail_bytes = 38953984
Oct 14 06:52:35 localhost kernel: [4269962.940657]   GH   cycle = 7, GH   bytes = 38953976

This started occurred a lot and the backups were working fine for a day
and then they started failing because they failed to remove the LVM
snapshot using `lvremove`. After a little bit of research I found this
commit in the linux kernel:
https://github.com/torvalds/linux/commit/3948659e30808fbaa7673bbe89de2ae9769e20a7
which seems to fix the exact same problem I'm having.

This commit fixes this issue form kernel version 3.4 onwards. The most
recent virtual kernel available for Ubuntu 12.04 LTS release is
"3.2.0-49-virtual". So the possible solutions are to either backport the
xfs fix to 3.2.x kernel or release virtual kernel releases for the
latest version of the kernel.

I'll be happy to provide more information regarding this issue.

** Affects: linux-meta (Ubuntu)
     Importance: Undecided
         Status: Confirmed


** Tags: bot-comment
-- 
Request for updated Ubuntu virtual kernel images
https://bugs.launchpad.net/bugs/1241848
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