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

Gerry Reno greno at verizon.net
Mon Apr 20 20:24:28 UTC 2009

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.
We need a way to these things:

1.  Have sysadmins enable the "monitor" when necessary.
2.  Be able to issue multi-Ctrl key (preferably user-defineable) 
sequences for performing actions with the hypervisor.
3.  Have every aspect of every command available in "monitor" available 
from an API.

Right now, I cannot gain access to the "monitor" in libvirt.  Therefore 
I cannot issue something like "savevm", "loadvm", or "commit hda" or any 
of these commands necessary for working with snapshots.  I also am 
unable to send Ctrl key sequences such as Ctrl-a-s to write the snapshot 
to the image file.  Therefore, all routes are closed.  The current 
approach of just locking everything down is wrong.  That decision should 
be left up to the user as to how much security they wish to enable in 
their particular environment.


More information about the libvir-list mailing list