On Tue, Jan 9, 2018 at 7:55 PM, Dr. David Alan Gilbert <dgilb...@redhat.com> wrote: >> Certain guest operations like rebooting or zeroing memory will defeat >> the incremental guest RAM snapshot feature. It's worth thinking about >> these cases to make sure this feature would be worth it in real use >> cases. > > But those probably wouldn't upset an NVDimm?
If the guest dirties all RAM then the incremental snapshot feature degrades to a full snapshot. I'm asking if there are common operations where that happens. I seem to remember Windows guests zero all pages on cold boot. Maybe that's not the case anymore. Worth checking before embarking on this feature because it could be a waste of effort if it turns out real-world guests dirty all memory in common cases.