Dominique wrote: > -----Original Message----- > From: Dominique Ramaekers > [mailto:dominique.ramaekers@xxxxxxxxxx] > Sent: Wednesday, December 02, 2015 1:34 PM > To: Lentes, Bernd; libvirt-ML > Subject: RE: snapshot of running vm's > > > > > -----Oorspronkelijk bericht----- > > Van: libvirt-users-bounces@xxxxxxxxxx [mailto:libvirt-users- > > bounces@xxxxxxxxxx] Namens Lentes, Bernd > > Verzonden: dinsdag 1 december 2015 16:31 > > Aan: libvirt-ML > > Onderwerp: snapshot of running vm's > > > > 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 ? > No > > > Or is it something I have to do explicitly (maybe via blockcommit) ? > When using external snapshots, the procedure works like this: > 1. Create external snapshot => a new file is created ex. 'image.qcow2' > 2. Backup the original file ex. 'image.raw' (this file wil not change over > time. All writes are done on image.qcow2). > 3. Active block commit (commits all writes done on image.qcow2 to > image.raw and activate image.raw) 4. delete image.qcow2 > > If you do a test, you can check which file is in use by 'virsh domblklist > $VM' > > > 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 ? > Yes. And it's advisible to also use --quiesce to flush the guests disk cache > (the guest agent needs to be installed and running on the guest) And > optional use --no-metadata to make shure libvirt isn't following up on > these snapshots. This way you can just remove the image.qcow2 with rm > > > Do I have to provide --live as a parameter ? > Yes, the snapshot is done on a live guest/disk > > > 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 ? > Yes, you have to update the guest xml with 'virsh edit $VM' and enter > these lines in the devices section <channel type='unix'> > <source mode='bind'> > <target type='virtio' name='org.qemu.guest_agent.0'/> </channel> > > After this, it's possible the qemu guest agent is still not working, edit the > xml again and change the port number in the line to a free port (you'll > see that for example spice is using the same controller, bus and port...) > <address type='virtio-serial' controller='0' bus='0' port='1'/> > > > > > > > Is this way of backup a good solution ? Is there something to improve, > This way you backup disk state. Most of the times this will be great. For > some applications, this isn't sufficient. > For instance, a Autodesk Vault Server has a SQL database and a separate > file storage. Using Active block commit to backup will not guarantee data > concistancy. That's why Autodesk has its own 'best practice'. Here I > initiate the Autodesk procedure through a powershell script (I connect to > the guest with telnet). > > > > 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 > You'll need libvirt 1.2.9 or more and Qemu 2.1 (with higher qemu's I have > experienced some trouble...) > > > > (what I don't like because I tried already to update my libvirt but > > had tons of > > dependencies) ? Ok. I have to try. > > > > I know. A lot of questions. But it's a backup, and I wanted to be sure > > that it operates properly. > > > > Thanks. > > > > Hi Dominique, thanks for your very clear and detailed answer. Bernd Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH) Ingolstaedter Landstr. 1 85764 Neuherberg www.helmholtz-muenchen.de Aufsichtsratsvorsitzende: MinDir'in Baerbel Brumme-Bothe Geschaeftsfuehrer: Prof. Dr. Guenther Wess, Dr. Nikolaus Blum, Dr. Alfons Enhsen Registergericht: Amtsgericht Muenchen HRB 6466 USt-IdNr: DE 129521671 _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
