[Qemu-devel] Re: KVM call agenda for Mar 16

["Daniel P. Berrange" <berrange@redhat.com>]

On Tue, Mar 16, 2010 at 09:29:44AM +0000, Daniel P. Berrange wrote:
> On Tue, Mar 16, 2010 at 10:18:03AM +0100, Juan Quintela wrote:
> > Chris Wright <chrisw@redhat.com> wrote:
> > > Please send in any agenda items you are interested in covering.
> > 
> > Migration:
> > - flexible migration:  I hope to sent an RFC patch on time for the
> >   call.  idea is to use subsections.
> > 
> > - callbacks.  block migration introduced several callbacks:
> >   * cancel()
> >   * get_status()
> >   * release()
> >   in spice we need now another to callbacks: on_start() and on_end().
> >    * on_start(): tells spice that migration has started (it will then
> >      manage certificates, passwords, ... itself)
> >    * on_end(): it is called when migration ends.  spice use it to
> >      transparently connect to the new host and user don't have to "reconnect"
> > 
> > - what to do on migration error:
> >   - target side:  libvirt folks want the program to print a message if
> >     it fails.  Current code spent 100% cpu time doing select on a closed
> >     fd.  (patches already on the list to make it wait without using
> >     cpu).
> 
> No, that is not correct. We want QEMU to exit when incoming migration
> fails. Printing to stderr is just something that will end up in the
> logs for admin to further diagnose the problem if required. There is 
> nothing to be gained by leaving QEMU running, and everything to loose
> since the failed migration may have left it in a dangerous state from 
> which you do not want to attempt incoming migration again.

Sorry, I forgot to include the original BZ report about this problem from
Fedora. In essence, we just truncated the original save state image and
then tried to restore from it to check handling in the event of corrupted
save image.

  https://bugzilla.redhat.com/show_bug.cgi?id=518032


Regards,
Daniel
-- 
|: Red Hat, Engineering, London    -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :|
|: http://autobuild.org        -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-   F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|