[libvirt] domblkstat not working for qemu-kvm > 0.11

[Daniel P. Berrange]

On Wed, Feb 10, 2010 at 04:58:25PM +0000, Daniel P. Berrange wrote:
> On Tue, Feb 09, 2010 at 04:06:56PM +0100, Thomas Treutner wrote:
> > Hi,
> > 
> > with all qemu-kvm > 0.11, virsh domblkstat is not working:
> > 
> > virsh -c qemu://node03/system domblkstat wp01 vdb :  invalid argument in no 
> > stats found for device virtio-disk1
> > 
> > (vda, vdb etc. works with 0.11)
> > 
> > "virtio-disk1" seems to be a red herring:
> > 
> > virsh -c qemu://node03/system domblkstat wp01 virtio-disk1 : invalid argument 
> > in invalid path: virtio-disk1
> > 
> > Most probably there have been made some changes with 0.12 libvirt does not 
> > resemble yet. If you need more debugging output, just tell.
> 
> I've managed to reproduce it and figured out what's wrong. libvirt was
> trying to match against the device name 'virtio-disk1' rather than against
> the drive name 'drive-virtio-disk1' and so not finding the stats.
> 
> The reason its matching 'virtio-disk1' rather than 'vda' is that that is
> the globally unique name libvirt gave to the 'vda' device. You can see
> this now in the XML format <alias> element. In the future we will allow
> you to actually pass the alias in directly, as an alternative to the
> 'vda' style name

FYI, I've added a test case for the disk stats API now & just posted the
fix to the list

http://libvirt.org/git/?p=libvirt-tck.git;a=blob;f=scripts/domain/120-disks-stats.t;hb=HEAD


Daniel
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