Ballooning problem

[SP5VTV]

Hi,
I have a problem with memory management. PVE 7.3-3, VM guest Windows server 2016. The newest Virtio driver installed (January 2023). When the balloon is on, Windows consuming all memory. In my case 20GB RAM. The system itself has low utilization. No service is running that would cause a heavy load and no one is logged in, and the memory utilization is around 90%. When I switch off balloning Windows consumes about 30% memory, but PVE reports about 95% used memory.
How many percent can I exaggerate memory with a dozen Windows VMs?
Greetings for all PVE Admins.

 

[leesteken]

When the host memory usage is at 80% (or the memory+swap is at 80% of total+swapspace), ballooning will take away memory from the VMs until they are at their minimum (setting per VM). So for 12 VMs, you need to set the minimum memory per VM to 6,67% of your system's memory (you did not specify).
If you want to over-commit memory by sharing identical memory pages between VMs, use KSM instead of ballooning.