libvirt users - Jun 2013 - Re: snapshot-create-as for a single disk not all disks

Hi everyone!
   Is there any way to create snaphot for a single disk of a virtual machine. As
I konw, "virsh snapshot-create-as domain_name  snapshot_name
--disk-only" traverses all block devices to create snapshot. However I
don't want to create snapshot except for root partition.
  The version of qemu and libvirt I used is as follows:
                qemu-1.4.2 and libvrit-0.10.2
  I meet an error when I delete the snapshot which is created by
"snapshot-create-as" command. whether or not qemu(1.4.2) and
libvirt(0.10.2) don't support the function currently.


   Look forward to your help!

I think what you're looking for is LVM snapshots. The whole purpose of
taking VM snapshots is to have a consistent image of the machine as a whole.
There's lots of articles out there on LVM snapshots, here's one.

   http://www.tldp.org/HOWTO/LVM-HOWTO/snapshots_backup.html

From: libvirt-users-bounces@redhat.com [mailto:libvirt-users-bounces@redhat.com]
On Behalf Of cmcc.dylan
Sent: Saturday, June 22, 2013 11:13 AM
To: libvirt-users@redhat.com
Subject: [libvirt-users] snapshot-create-as for a single disk not all disks

Hi everyone!
   Is there any way to create snaphot for a single disk of a virtual machine. As
I konw, "virsh snapshot-create-as domain_name  snapshot_name
--disk-only" traverses all block devices to create snapshot. However I
don't want to create snapshot except for root partition.
  The version of qemu and libvirt I used is as follows:
                qemu-1.4.2 and libvrit-0.10.2
  I meet an error when I delete the snapshot which is created by
"snapshot-create-as" command. whether or not qemu(1.4.2) and
libvirt(0.10.2) don't support the function currently.

   Look forward to your help!

Thanks for you reply!
    Firstly, I'm very sorry I forgot introduce the scenarios in my
experiments. Supposing a case, I have a virtual machine with two disks. One is
mounted as a root partition and the other is data partition and the second disk
is an iscsi lun, that is to say, not a local disk or image. Now the result
wanted is that creating a snapshot for the root disk but not for the data disk
when executing "virsh snapshot-create-as" command. Actually, it meet
an error:
      error:unsuported configuration: source for disk 'vdc' is not a
regular file; refusing to generate external snapshot name.
    The xml configuration of this virtual machine as follows:
         <disk type='block' device='disk'>
              <driver name='qemu' type='raw' />
             <source dev='/dev/sdm1' >                 // sdm1 is
a remote scsi lun and mounted at the local host
              <target dev='vdc' bus='virtio' />
         </disk>
     Given above problem, I want to only create the snapshot of local disk.




在 2013-06-24 23:22:47，"vonNieda, Adam (USMS)"
<Adam.vonNieda@usdoj.gov> 写道：


 

   I think what you’re looking for is LVM snapshots. The whole purpose of taking
VM snapshots is to have a consistent image of the machine as a whole. There’s
lots of articles out there on LVM snapshots, here’s one.

 

   http://www.tldp.org/HOWTO/LVM-HOWTO/snapshots_backup.html

 

From:libvirt-users-bounces@redhat.com [mailto:libvirt-users-bounces@redhat.com]
On Behalf Of cmcc.dylan
Sent: Saturday, June 22, 2013 11:13 AM
To:libvirt-users@redhat.com
Subject: [libvirt-users] snapshot-create-as for a single disk not all disks

 

Hi everyone!

   Is there any way to create snaphot for a single disk of a virtual machine. As
I konw, "virsh snapshot-create-as domain_name  snapshot_name
--disk-only" traverses all block devices to create snapshot. However I
don't want to create snapshot except for root partition.

  The version of qemu and libvirt I used is as follows:

                qemu-1.4.2 and libvrit-0.10.2

  I meet an error when I delete the snapshot which is created by
"snapshot-create-as" command. whether or not qemu(1.4.2) and
libvirt(0.10.2) don't support the function currently.

 

   Look forward to your help!