[libvirt-users] Transient VM Usage

[Michal Privoznik]

On 11.09.2015 11:34, Mcburn wrote:
> Hey at all,
> 
> my Name is Jens-Uwe Sperling. Iám a young student in computer science.
> I want install a VM for testing at home.
> 
> i had install a VM with virt-install and the default parameters. (Number
> cpu, mem etc.)
> 
> After that i install my OS and configure it.
> 
> Now i want work on this image in a transient way.
> So i can use the OS with the given config but every change i do from now
> should not change my image.
> 
> I found three ways to do that:
> 
>   -  Make a snapshot from my image and kill the snapshot after using.

Yes, this will work perfectly.

>   -  Using the transient option in the xml file under disk.

Wow, I didn't even know we have such element.

>   -  Making a qcow2 image and run that.

You mean copy the original image and run from that copy?

The first option has advantage, that you can save the progress or drop
it if you don't like it. I mean, you'll create a snapshot, and then
continue using the guest. As time moves on, you may find out that you
actually want the state to be persistent, so you merge the active layer
into the base. If not, then just drop it. With option #2 you don't have
this opportunity.
Option #3 is like #1 except that you're doing the snapshot yourself :)

Michal