[buildd-tools-devel] Bug#592250: Bug#592250: schroot: LVM snapshots not fully cleaned up

[Roger Leigh]

On Sun, Aug 08, 2010 at 01:08:57PM -0400, James Vega wrote:
> Package: schroot
> Version: 1.4.7-1
> Severity: normal
> 
> As the attached typescript should show, when schroot is finished running
> commands in an LVM snapshot chroot, the snapshot is not properly torn
> down.  This leads to an accumulation of active snapshots.

> I: Executing ‘05lvm setup-start ok’
> E: 05lvm:     Setting chunksize to 8 sectors.
> E: 05lvm:     Setting logging type to disk
> E: 05lvm:     Finding volume group "debil0"
> E: 05lvm:     Archiving volume group "debil0" metadata (seqno 1378).
> E: 05lvm:     Creating logical volume sid-1bb5a5c0-6fe6-4c52-ae4c-31d39cdb48df
> E: 05lvm:     Creating volume group backup "/etc/lvm/backup/debil0" (seqno 1379).
> E: 05lvm:     Found volume group "debil0"
> E: 05lvm:     Creating debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df
> E: 05lvm:     Loading debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df table (254:9)
> E: 05lvm:     Resuming debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df (254:9)
> E: 05lvm:     Clearing start of logical volume "sid-1bb5a5c0-6fe6-4c52-ae4c-31d39cdb48df"
> E: 05lvm:     Creating logical volume snapshot1
> E: 05lvm:     Found volume group "debil0"
> E: 05lvm:     Found volume group "debil0"
> E: 05lvm:     Loading debil0-schroot-real table (254:6)
> E: 05lvm:     Suppressed debil0-schroot-real identical table reload.
> E: 05lvm:     Loading debil0-schroot table (254:5)
> E: 05lvm:     Suppressed debil0-schroot identical table reload.
> E: 05lvm:     Loading debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59-cow table (254:7)
> E: 05lvm:     Suppressed debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59-cow identical table reload.
> E: 05lvm:     Loading debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59 table (254:4)
> E: 05lvm:     Suppressed debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59 identical table reload.
> E: 05lvm:     Creating debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df-cow
> E: 05lvm:     Loading debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df-cow table (254:10)
> E: 05lvm:     Resuming debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df-cow (254:10)
> E: 05lvm:     Loading debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df table (254:9)
> E: 05lvm:     Suspending debil0-schroot (254:5) with filesystem sync with device flush
> E: 05lvm:     Suspending debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59 (254:4) with filesystem sync with device flush
> E: 05lvm:     Suspending debil0-schroot-real (254:6) with filesystem sync with device flush
> E: 05lvm:     Suspending debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59-cow (254:7) with filesystem sync with device flush
> E: 05lvm:     Found volume group "debil0"
> E: 05lvm:     Loading debil0-schroot-real table (254:6)
> E: 05lvm:     Suppressed debil0-schroot-real identical table reload.
> E: 05lvm:     Loading debil0-schroot table (254:5)
> E: 05lvm:     Suppressed debil0-schroot identical table reload.
> E: 05lvm:     Loading debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59-cow table (254:7)
> E: 05lvm:     Suppressed debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59-cow identical table reload.
> E: 05lvm:     Loading debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59 table (254:4)
> E: 05lvm:     Suppressed debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59 identical table reload.
> E: 05lvm:     Loading debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df-cow table (254:10)
> E: 05lvm:     Suppressed debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df-cow identical table reload.
> E: 05lvm:     Resuming debil0-schroot-real (254:6)
> E: 05lvm:     Resuming debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59-cow (254:7)
> E: 05lvm:     Resuming debil0-experimental--dd3bfc99--a737--4a75--a1db--68153d95db59 (254:4)
> E: 05lvm:     Resuming debil0-sid--1bb5a5c0--6fe6--4c52--ae4c--31d39cdb48df (254:9)
> E: 05lvm:     Resuming debil0-schroot (254:5)
> E: 05lvm:     Creating volume group backup "/etc/lvm/backup/debil0" (seqno 1380).
> I: 05lvm:   Logical volume "sid-1bb5a5c0-6fe6-4c52-ae4c-31d39cdb48df" created


> I: Executing ‘05lvm setup-stop ok’
> I: 05lvm: Removing device lock for /dev/debil0/sid-1bb5a5c0-6fe6-4c52-ae4c-31d39cdb48df, owned by pid 31620
> E: 05lvm:     Using logical volume(s) on command line
> E: 05lvm:   Can't remove open logical volume "sid-1bb5a5c0-6fe6-4c52-ae4c-31d39cdb48df"

The question here is why did the lvremove command above fail?  What
happens if you lvremove sid-1bb5a5c0-6fe6-4c52-ae4c-31d39cdb48df
by hand?  Does this still give you the same error?

Which kernel version are you running?  Some versions do have buggy
LVM support--I've seen myself some time ago a system which would
allow snapshot creation but not deletion.  IIRC it might also be
due to the presence of multiple snapshots or snapshots of snapshots--
you might see this go away if you delete all snapshots in this
volume group and try again.  This might fix things if the LVM
metadata is screwed up and helped me once (but I'm not sufficiently
knowledgable regarding LVM that I know why this helped).


Regards,
Roger

-- 
  .''`.  Roger Leigh
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