Open Stack

On Fri, Oct 02, 2015 at 06:20:31AM +0000, Koniszewski, Pawel wrote:
> > -----Original Message-----
> > From: Mathieu Gagné [mailto:mgagne at internap.com]
> > Sent: Thursday, October 1, 2015 7:24 PM
> > To: OpenStack Development Mailing List (not for usage questions)

[. . .]

> > >> I have taken the liberty of listing those that responded to the
> > >> thread and the authors of mentioned patches as interested people.
> > >
> > >> From the responses and looking at the specs up for review it looks
> > >> like there are about five areas that could be addressed in Mitaka and
> > >> several others that could come later. The first five are:
> > >>
> > >>
> > >> - migrating instances with a mix of local disks and cinder volumes
> > >
> > > IIUC, this is possible with the selective block device migration work
> > > merged in upstream libvirt:
> > >
> > >     https://www.redhat.com/archives/libvir-list/2015-May/msg00955.html
> > >
> > 
> > Can someone explain to me what is the actual "disk name" I have to pass in
> > to libvirt? I couldn't find any documentation about how to use this
> feature.
> 
> You have to pass device names from /dev/, e.g., if a VM has ephemeral disk
> attached at /dev/vdb you need to pass in 'vdb'. Format expected by
> migrate_disks is "<device_name1>,<device_name2>...".

Yeah, you can enumerate the current block devices for an instance by
doing:

    $ virsh domblklist instance-00000001

[If you're curious, the 'v' in the 'vda/vdb' stands for 'virtio' disks.
For non-virtio disks, you'd see a device name like 'hda'.]

-- 
/kashyap