Disk in snapshot mode

[Ján ONDREJ (SAL)]

Hello,

can I set snapshot mode for KVM disk emulation using virsh or/and
virt-manager? This is a great feature to test software using qemu/kvm, but I
don't see, how to use this using withou direct running of qemu-kvm
-snapshot.

In snapshot mode qemu does not change original disk file, but changes are
written to temporary files and after shutdown changes are lost. It's good to
use when trying something on virtual machien. As an opensource software
developer I often need to test my software and then forget all changes in
system.

Running kvm using commandline work well, just it's a bit hard to setup
devides same way as they are done in libvirt.

Snapshot mode can be set 2 ways, by adding "-snapshot" qemu parameter or
adding ",snapshot=on" to -drive parameter.

May be an universal option in XML definitions to add unknown parameters
may be useful, for example:
  <append>,snapshot=on</append>

Regards
    			SAL