dmevent can not open shared object file libdevmapper-event-lvm2snapshot.so leads to lvcreate/lvremove being slow
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
lvm2 (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
1) lsb_release -rd
Description: Ubuntu Xenial Xerus (development branch)
Release: 16.04
2) apt-cache policy lvm2
lvm2:
Installed: 2.02.133-1ubuntu7
Candidate: 2.02.133-1ubuntu7
Version table:
*** 2.02.133-1ubuntu7 500
500 http://
100 /var/lib/
3) Expected lvcreate/lvremove test to take less than a second
4) It took about 30 seconds instead
To reproduce
============
Use the script.
export GROUP='group-test'
export VOLUME=
export SNAPSHOT=
export BACKING_
if ! vgs -o name | grep $GROUP; then
dd if=/dev/zero of=$BACKING_FILE bs=1M count=2000
losetup /dev/loop100 $BACKING_FILE
pvcreate /dev/loop100
vgcreate $GROUP /dev/loop100
fi
lvcreate -n $VOLUME $GROUP -L 1g
lvcreate --name $SNAPSHOT --snapshot $GROUP/$VOLUME -L 1.00g
lvremove -f $GROUP/$SNAPSHOT
time lvremove -f $GROUP/$VOLUME
During lvcreate/lvremove, /var/log/syslog would show:
Mar 23 15:39:59 xenial-
Workaround
==========
In /etc/lvm/lvm.conf, change snapshot_library to use absolute path:
snapshot_library = "/lib/powerpc64
The workaround is obviously would only work for the specific architecture. A
proper fix would be to find out why dmevent can not load the library, and fix
that.
Additional Notes
================
I have also tested this on Xenial x86 VM, and on baremetal install of Xenial.
Had the same problem on both.
This bug was fixed in the package lvm2 - 2.02.133-1ubuntu10
--------------- 1ubuntu10) xenial; urgency=medium
lvm2 (2.02.133-
* Cherry-pick change from lvm2 2.02.133-2 in Debian to move event plugins
back onto the main library patch, which fixes problems with monitoring
failing for snapshots and raid volumes. Closes: #807279, LP: #1556451,
LP: #1561228.
-- Steve Langasek <email address hidden> Sat, 16 Apr 2016 00:06:53 -0700