[libvirt-users] snapshot of running vm's

[Lentes, Bernd]

Hi,

i'd like to create snapshots of my running vm's. I have several hosts with
SLES11 SP4 64bit. I use libvirt 1.2.5-7.1 . VM's are Windows 7, SLES,
Ubuntu, Opensuse.
I use raw files for the vm's.
I try to orientate myself by
http://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit .
The hosts are backuped every night by a network based backup solution
(Legato).
My idea is:

- delete any existing snapshot
- create a new snapshot
- of course before Legato arrives
- then Legato might come and saves my snapshot
- next night the same


Questions:
When I delete a snapshot, is it merged automatically with its base image ?
Or is it something I have to do explicitly (maybe via blockcommit) ?
How can I get rid of the unused snapshot afterwards ? just rm ?
Because I'm doing a live backup do I need to create an external snapshot ?
To create an external snapshot do I have to provide --disk-only ?
Do I have to provide --live as a parameter ?
I tried --quiesce but got that message:

virsh # snapshot-create --domain sles11 --atomic --disk-only --quiesce
error: argument unsupported: QEMU guest agent is not configured
The system I'm testing with is SLES11 SP4 (host and guest).  I installed
the guest agent:

vm58820-8:~ # rpm -q qemu-guest-agent
qemu-guest-agent-2.0.2-1.35
Is there something I have to configure ?

Is this way of backup a good solution ? Is there something to improve,
something I have to take care of ?
Is this backup consistent ?
Does that all work with libvirt 1.2.5-7.1 or do I need a more recent
version (what I don't like because I tried
already to update my libvirt but had tons of dependencies) ?

I know. A lot of questions. But it's a backup, and I wanted to be sure
that it operates properly.

Thanks.


Bernd
--
Bernd Lentes

Systemadministration
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bernd.lentes at helmholtz-muenchen.de
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fax: +49 (0)89 3187 2294

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