Re: [libvirt] [PATCH] qemu: snapshot: Keep non-persistent changes alive in snapshot

On 10/27/2017 02:51 PM, Jiri Denemark wrote: > I think this is actually a bit more complicated. When reverting to a > snapshot, when reverting a snapshot we should revert both active and > inactive configuration for backward compatibility and also because it > makes sense. Imagine you made a snapshot of a running domain, played > with the domain configuration and then reverted the state of the domain > to the snapshot. Once you shutdown the domain and start it again you'd > get a completely different machine. Of course, you actually may want > such behavior. Thus we can't really guess whether a user wants to revert > both active and inactive configuration or just one of them. The user > should be able to tell us what to do (and we should revert both configs > if no preference is given). > > However, for this to be really useful we need to store both active and > inactive configurations when creating a snapshot of a running domain. With the current behavior that I see from snapshot-list, I understood we categorize the snapshots as "Active (running, paused)" or "config(shutoff)" depending if the snapshot was taken on an active or inactive domain. With my use case what I observed was that the revert of active snapshot actually overwriting inactive domain configuration. I thought only the "config" snapshot alone can overwrite the inactive domain configuration. Hence this patch. Are you suggesting we should have both active and inactive domain configurations to be saved for an active guest and restore (both by default) OR (provide options to select)?