[libvirt] [PATCH v9] support offline migration

[li guang]

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.
I'll try to save config normally.

> 
> Also the '--undefinesource' flag appeared to have no effect at all. The
> guest still exists on the source, both in libvirtd & on disk.
> 

Yes, I did fail to take care of it, thanks!

> 
> Daniel

-- 
liguang    lig.fnst at cn.fujitsu.com
FNST linux kernel team