Hi Rich,
Sorry if my mail annoys you.
Actually I have tested the QEMU KVM snapshot features with multiple
overlays and found it to be working fine.
Let’s say for an example, I have installed Windows XP as a QEMU virtual
machine (The name of the VM is ‘winxp’). Then I created two separate
overlays on top of ‘winxp’ as ‘winxp-vm01’ and ‘winxp-vm02’ and renamed the
overlay images accordingly on the OS level.
Then I created another overlay on top of ‘winxp-vm01’ as ‘winscp’, boot the
overlay image ‘winscp’ and installed WinSCP on it.
Third step what I did was create another overlay file on top of ‘winscp’ as
‘7zip’ and installed 7ZIP on top of it.
The current scenario is like the following :-
/winxp-vm01
---------> winscp ----------> 7zip ------- User1
/
/
winxp vm
\
\
\winxp-vm02
---------- User2
So if User1 starts the 7zip overlay image using qemu-kvm, he'll be able to
see WinSCP and 7ZIP installed and the VM name as 'winxp-vm01'.
So the question is is there any way we can move or copy the two overlays on
top of 'winxp-vm02' so that the scenario look like the following:-
/winxp-vm01 ---------
User1
/
/
winxp vm
\
\
\winxp-vm02
---------->winscp -----------> 7zip ------- User2
So if User2 starts the 7zip overlay image using qemu-kvm, he'll be able to
see WinSCP and 7ZIP installed and the VM name as 'winxp-vm02'.
I tried with 'qemu-img rebase' option to simulate the above scenario, but
unable to do that.
If this QEMU feature along with 'Libguestfs(which can be utilized to change
parameters inside Windows VMs) integrates with oVirt/RHEV , then we can
have a good solutions for VDI scneario.
Again sincere apologies from my side, my intention was not to know the
internals of any proprietary software, but as a follower of QEMU KVM I was
just curious to know if application layering can be done with QEMU.
Please put your valued input into this.
Thanks
Kausik
On Thu, Jan 9, 2014 at 3:57 AM, Richard W.M. Jones <rjo...@redhat.com>wrote:
> On Wed, Jan 08, 2014 at 11:37:44PM +0530, kausik pal wrote:
> > Hi rich,
> >
> > Thanks for the answer.
> >
> > I was wondering how unidesk has solved the problem using disk layering.
> > They have the solution for VMware, so if similar feature can be built on
> > qemu for KVM hypervisor then we will have a great solution for
> application
> > management from VDI perspective.
>
> I have no knowledge or interest in how proprietary software works.
>
> Rich.
>
> --
> Richard Jones, Virtualization Group, Red Hat
> http://people.redhat.com/~rjones
> virt-top is 'top' for virtual machines. Tiny program with many
> powerful monitoring features, net stats, disk stats, logging, etc.
> http://people.redhat.com/~rjones/virt-top
>
