Public bug reported:

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://ports.ubuntu.com/ubuntu-ports xenial/main ppc64el Packages
        100 /var/lib/dpkg/status

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='volume-test'
  export SNAPSHOT='_snapshot-test'
  export BACKING_FILE=/root/lvmbacking

  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-server-2016-01-18-ppc64el dmeventd[2753]: dmeventd 
libdevmapper-event-lvm2snapshot.so dlopen failed: 
libdevmapper-event-lvm2snapshot.so: cannot open shared object file: No such 
file or directory.


Workaround
==========

In /etc/lvm/lvm.conf, change snapshot_library to use absolute path:

  snapshot_library = "/lib/powerpc64le-linux-gnu/device-mapper
/libdevmapper-event-lvm2snapshot.so"

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.

** Affects: lvm2 (Ubuntu)
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1561228

Title:
  dmevent can not open shared object file libdevmapper-event-
  lvm2snapshot.so leads to lvcreate/lvremove being slow

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/lvm2/+bug/1561228/+subscriptions

-- 
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to