[libvirt-users] is it possible to create a snapshot from a guest residing in a plain partition ?

[Lentes, Bernd]

----- On Apr 3, 2019, at 5:27 PM, Eric Blake eblake at redhat.com wrote:



> It is possible to create an external snapshot (an internal one is not
> possible, unless you stored the guest disk as qcow2 format embedded
> inside the partition rather than directly as raw format).  Note that
> when you create an external snapshot, the partition becomes a read-only
> point in time (no further updates to that partition), and your new
> file.sn qcow2 wrapper file created by the snapshot operation stores all
> subsequent guest writes. (Well, unless you decide to do a commit
> operation to push the changes from the overlay back into the base file
> and get rid of the overlay)

Hi Eric,

thanks for your answer.
i tried it:

virsh # snapshot-create-as --disk-only --name sn --domain sim
error: unsupported configuration: source for disk 'vdb' is not a regular file; refusing to generate external snapshot name

This is the snippet from the conf for the guest:

<disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source dev='/dev/vg_san/lv_sim'/>
      <backingStore/>
      <target dev='vdb' bus='virtio'/>
      <alias name='virtio-disk1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </disk>

I'm running SLES 12 SP4 with libvirt 4.0.0-6.13.x86_64.

Any ideas ?


Bernd
 

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