lvm volumes not listed if lvm has command_names option = 1

[Dave Gilbert]

I have an lvm vg called 'main' in which I keep images for my VMs and a few other things in. It's configured as a storage pool in libvirt:

sudo cat /etc/libvirt/storage/main.xml
<pool type='logical'>
  <name>main</name>
  <uuid>507fc133-c479-ec69-fb3e-1a2693ce27c3</uuid>
  <capacity>0</capacity>
  <allocation>0</allocation>
  <available>0</available>
  <source>
    <name>main</name>
    <format type='lvm2'/>
  </source>
  <target>
    <path>/dev/main</path>
    <permissions>
      <mode>0700</mode>
      <owner>0</owner>
      <group>0</group>
    </permissions>
  </target>
</pool>

virsh vol-list main wasn't working for me, after a bit of prodding I found the issue was that in /etc/lvm/lvm.conf I'd set

command_names = 1

in the 'log' section (having tried to debug some other lvm issues).

I'm going to say also this might be an lvm bug - I think command_names is actually changing the output format of the lvm commands, not just what's logged, and for an option in the log section of /etc/lvm/lvm.conf that's probably wrong.

Dave

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: libvirt-bin 0.9.2-4ubuntu11
ProcVersionSignature: Ubuntu 3.0.0-9.14-generic 3.0.3
Uname: Linux 3.0.0-9-generic x86_64
Architecture: amd64
CheckboxSubmission: f2d10bd9f943a85b486a282e7840a570
CheckboxSystem: 0531969bcfd4f03af7405c98dc94a948
Date: Sun Aug 28 23:53:51 2011
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: libvirt
UpgradeStatus: Upgraded to oneiric on 2011-07-31 (28 days ago)
modified.conffile..etc.libvirt.libvirtd.conf: [modified]
modified.conffile..etc.libvirt.qemu.networks.default.xml: [modified]
mtime.conffile..etc.libvirt.libvirtd.conf: 2011-08-28T23:35:06.483917
mtime.conffile..etc.libvirt.qemu.networks.default.xml: 2010-05-16T16:51:54.363311

[Marc Deslauriers (mdeslaur)]

This, and possibly other parsing issues in libvirt's storage_backend_logical.c is causing LVM bugs with virt-manager. See bug 551432.

[Dave Walker (davewalker)]

@Marc, do you believe this is Invalid with lvm2, therefore limited to how libvirt handles the xml markup?

Has this been raised upstream?

Thanks.

[Serge Hallyn (serge-hallyn)]

I think this would be legitimate as a bug against lvm for spitting out the command_name prefix when --noheadings is specified. However, changing existing behavior is always bad, and this should be easy enough to work around in libvirt, so I'll work on a patch for that.

[Alasdair G. Kergon (agk2)]

On Wed, Sep 07, 2011 at 03:28:45PM -0000, Serge Hallyn wrote:
> I think this would be legitimate as a bug against lvm for spitting out
> the command_name prefix when --noheadings is specified.

--noheadings only refers only to the headings line.

command_names applies to all output lines.

The option exists because LVM1 output used to look like that and this
option was to try to ease the transition to LVM2.

Alasdair

[Serge Hallyn (serge-hallyn)]

Patch sent upstream for discussion:

https://www.redhat.com/archives/libvir-list/2011-September/msg00590.html

[Serge Hallyn (serge-hallyn)]

This fix came in to precise through upstream.