libvirt users - Mar 2019 - KVM - full system ( disk+memory) snapshot by excluding the raw disks

Hi There , 

  I  have KVM VM with 4 qcow2 disks and 2 raw disks .  when I  try to take full
system snapshot by excluding raw disks . it is give below error . can you help
me how to fix this ?.  or is it possible to take full system snapshot in this
case .?.

 

When I change XMl as internal snapshots for raw disks . It throws a message
snapshot are not supported on war disks .

 

[root@localhost oscgpkg-7eee963550ba9e5b]# virsh snapshot-create --domain oscg2
--xmlfile oscgsnapshot.xml

error: unsupported configuration: disk 'vda' must use snapshot mode
'internal'

 

[root@localhost oscgpkg-7eee963550ba9e5b]#

 

 

 

 

[root@localhost oscgpkg-7eee963550ba9e5b]# cat oscgsnapshot.xml

<domainsnapshot>

  <description>oscg snapshot</description>

   <memory snapshot='internal'/>

  <disks>

    <disk name='hda' snapshot='internal'>

    </disk>

    <disk name='hdb' snapshot='internal'>

    </disk>

    <disk name='hdc' snapshot='internal'>

    </disk>

    <disk name='hdd' snapshot='internal'>

    </disk>

    <disk name='vda' snapshot='no'>

    </disk>

    <disk name='vdb' snapshot='no'>

    </disk>

  </disks>

</domainsnapshot>

On Fri, Mar 15, 2019 at 12:52:06 +0000, Suresh Babu Kandukuru
wrote:
> Hi There , I  have KVM VM with 4 qcow2 disks and 2 raw disks .  when I
> try to take full system snapshot by excluding raw disks . it is give
> below error . can you help me how to fix this ?.  or is it possible to
> take full system snapshot in this case .?.
No. For internal snapshots the qemu APIs don't support any form of
selecting which disks to include in a snapshots and which to omit.

This means that for a successful internal snapshot you need all disks to
be qcow2.

>  
> When I change XMl as internal snapshots for raw disks . It throws a
> message snapshot are not supported on war disks . 
>  
> [root@localhost oscgpkg-7eee963550ba9e5b]# virsh snapshot-create
> --domain oscg2 --xmlfile oscgsnapshot.xml error: unsupported
> configuration: disk 'vda' must use snapshot mode 'internal'
This error message is based on the inherent limitation of internal
snapshots.

You can try to use external snapshots where it is possible to snapshot
anything (even raw disks, by adding a qcow2 overlay). Unfortunately
external snapshots don't work with 'Revert' and 'Delete'
snapshot APIs.