If I had an XCP-NG server with 16GB RAM, and launched two VMs each with a min of 4GB and a max of 8GB, and internally each is running a Java app with 7GB Heap (which is pre-allocated), does XCP-NG allow more VMs to be created after startup, or will the JVM Heap allocation lock those first two VMs to the max memory ?
I’m basically wondering if I can overprovision the memory, and what happens at the point of too many VMs needing resource. Is it a crash, or just excessive disk paging somewhere ?
The use-case is running Java servers for testing, but also being able to fire up others temporarily when the system isn’t under load, whilst still ensuring things won’t just fallover.
Like many things, I realise this is not good practice and wouldn’t use it in production.