Re: [libvirt-users] Freeze Windows Guests For Consistent Storage Snapshots
On 12/10/2014 11:40 PM, Payes Anand wrote:
Hi,
Is it possible to freeze windows guests for a consistent storage level
snapshot.
Yes, if you install qemu-guest-agent in the guest, and wire up your
libvirt XML to have the guest-agent channel available. Once you have
done that, use the --quiesce flag as part of creating your snapshots.
I was able to freeze Centos guests by issuing the command:
virsh qemu-agent-command <guest_ID>
'{"execute":"guest-fsfreeze-freeze"}'
That is an unsupported backdoor, because it relies on libvirt-qemu.so.
You should really prefer the libvirt commands from libvirt.so instead
(the --quiesce flag to 'virsh snapshot-create[-as]'), because it is less
likely to get libvirt out of sync by going behind libvirt's back. Also,
libvirt 1.2.5 introduced 'virsh domfsfreeze' as the official way to do a
guest-agent 'guest'fsfreeze-freeze' command, although since you are
using older CentOS builds, your libvirt does not yet have that command
supported.
For CentOS guests, I enabled access between compute nodes and guests
through a socket by setting metadata parameter, hw_qemu_guest_agent=yes for
the guest image.
And then installing qemu-guest-agent inside the guest.
What steps do i have to follow for windows ?
The same steps - qemu-guest-agent is available for both Linux and
Windows guests.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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