I'm back
I had some time recently to make tests, So yes, it works !
Same process on my host with 32GB of physical RAM:
Start VM1, run stress-ng to take 100% (20GB) of RAM, stop stress-ng
Start VM2, run a command that take slowly 18GB of ram by 10Mb/s (command : #</dev/zero head -c 18000m | pv...