[libvirt] [PATCH v9] support offline migration

[Daniel P. Berrange]

On Thu, Oct 11, 2012 at 10:43:14AM +0800, li guang wrote:
> 在 2012-10-10三的 14:38 +0100，Daniel P. Berrange写道：
> > On Tue, Sep 25, 2012 at 03:45:24PM +0800, liguang wrote:
> > > original migration did not aware of offline case,
> > > so, try to support offline migration quietly
> > > (did not disturb original migration) by pass
> > > VIR_MIGRATE_OFFLINE flag to migration APIs if only
> > > the domain is really inactive, and
> > > migration process will not puzzled by domain
> > > offline and exit unexpectedly.
> > > these changes did not take care of disk images the
> > > domain required, for them could be transferred by
> > > other APIs as suggested, then VIR_MIGRATE_OFFLINE
> > > should not combined with VIR_MIGRATE_NON_SHARED_*.
> > > so, this migration result is just make domain
> > > definition alive at target side.
> > > 
> > > Signed-off-by: liguang <lig.fnst at cn.fujitsu.com>
> > > ---
> > >  include/libvirt/libvirt.h.in |    1 +
> > >  src/qemu/qemu_driver.c       |   15 ++++++++++++
> > >  src/qemu/qemu_migration.c    |   53 ++++++++++++++++++++++++++++++++++++-----
> > >  src/qemu/qemu_migration.h    |    3 +-
> > >  tools/virsh-domain.c         |    6 ++++
> > >  5 files changed, 70 insertions(+), 8 deletions(-)
> > 
> > In my testing this patch is still badly broken, apparently no different
> > than the previous version I tested
> > 
> > I have 2 hosts, avocado & mustard and stopped guest vm1. I try to
> > migrate the VM from avocado to mustard thus:
> > 
> >  # ./tools/virsh -c qemu+ssh://root@avocado/system migrate --undefinesource --offline vm1 qemu+ssh://root@mustard/system
> > 
> > This should *not* even run because I did not pass the --persistent flag,
> > but it does in fact complete. I creates a guest 'vm1' on the target host,
> > but does not write out any config. This is a completely bogus scenario.
> > If a guest has no config, it is transient and thus must not exist if it
> > is shutoff, but your patch is resulting in a transient, shutoff guest.
> > 
> > If I set the '--persistent' flag, there is no diffrence in behaviour. We
> > still get a transient shutoff guest on the target.
> 
> pretty logical requirement,
> actually, you've got it located at for
> example /var/run/libvirt/qemu/dom.xml,
> and it's really persistent.

No, there should not be any file created in /var/run/libvirt/qemu/dom.xml
That directory is *only* for XML of guests which are *running*.

Dainel
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