[libvirt] F10: how to save snapshot back to image?

[Daniel P. Berrange]

On Mon, Apr 20, 2009 at 12:08:48PM -0400, Gerry Reno wrote:
> In Fedora 10 I've managed to get libvirt to call the emulator with 
> custom arguments so I can invoke -snapshot.  I just replaced the 
> emulator in /usr/bin with my own script which adds the argument and then 
> calls the original emulator.  This works fine.  And the snapshot works 
> fine.  I can make lots of changes and when I shutdown and restart then 
> all the changes are forgotten.  Now after I'm satisfied with some 
> changes I want to save the snapshot back to the image file.  I've tried 
> "Ctrl-Alt-s", but this does not work.  I tried finding the QEMU console, 
> but Serial Console is grayed out in the menu.  I don't know if that 
> would help anyway since this was a raw image and not qcow2 so I don't 
> think 'savevm' and 'loadvm' would work with raw. 
> 
> Can someone tell me how to save these snapshots back to the image file?  
> Thanks.

That's not supported at this time. The built in QCow2 snappshotting in
QEMU is also rather dangerous with it known to corrupt data in a number
of circumstances. We'd like to expose this functionality in libvirt
eventually, but we've not made it a priority yet since its not really
considered stable upstream either.

Daniel
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