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+ [Cinder] and [Tempest] in the $subject since this affects them too

On Thu, Apr 9, 2015 at 4:22 AM, Eric Blake <eblake at redhat.com> wrote:

> On 04/08/2015 12:01 PM, Deepak Shetty wrote:
> >
> > Questions:
> >
> > 1) Is this a valid scenario being tested ? Some say yes, I am not sure,
> > since the test makes sure that instance is OFF before snap is deleted and
> > this doesn't work for fs-backed drivers as they use hyp assisted snap
> which
> > needs domain to be active.
>
> Logically, it should be possible to delete snapshots when a domain is
> off (qemu-img can do it, but libvirt has not yet been taught how to
> manage it, in part because qemu-img is not as friendly as qemu in having
> a re-connectible Unix socket monitor for tracking long-running progress).
>

Is there a bug/feature already opened for this ? I didn't understand much
on what you
mean by re-connectible unix socket :)... are you hinting that qemu-img
doesn't have
ability to attach to a qemu / VM process for long time over unix socket ?

Looks like many believe that this should be a valid scenario but it
currently breaks the
fs-backed cinder drivers as the testcase proves.


>
> >
> >
> > 2) If this is valid scenario, then it means libvirt.py in nova should be
> > modified NOT to raise error, but continue with the snap delete (as if
> > volume was not attached) and take care of the dom xml (so that domain is
> > still bootable post snap deletion), is this the way to go ?
>
> Obviously, it would be nice to get libvirt to support offline snapshot
> deletion, but until then, upper layers will have to work around
> libvirt's shortcomings.  I don't know if that helps answer your
> questions, though.
>

Thanks, it does in a way.

Q to Tempest folks,
    Given that libvirt doesn't support this scenario yet, can fs-backed
cinder drivers affected
by this be able to skip this testcase (using storage_protocol = 'glusterfs'
for
gluster case) until either this is supported by libvirt or some workaround
in Nova is
decided upon ?

Appreciate your inputs.

thanx,
deepak
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