Inside each VM, you need to use performance monitor counter \Memory\Available Mbytes.which display the amount of physical memory available to the Hyper-V host operating system.
The following guidelines apply when measuring the value of this performance monitor counter:
- 50% of free memory available or more = Healthy
- 25% of free memory available = Monitor
- 10% of free memory available = Warning
- Less than 5% of free memory available = Critical, performance will be adversely affected
Another counter that you must monitor is \Memory\Pages/sec measures the rate at which pages are read from or written to disk to resolve hard page faults.
The following guidelines apply when measuring the value of this performance monitor counter:- Less than 500 = Healthy
- 500 - 1000 = Monitor or Caution
- Greater than 1000 = Critical, performance will be adversely affected
Note: Guidelines is retrieve from Microsoft site.
If \Memory\Available Mbytes. reached below 10% of free memory available and \Memory\Pages/sec is showing greater than 1000, you should add more memory to the VM
If \Memory\Available Mbytes is showing more than 50% of free memory available and \Memory\Pages/sec is less than 250, you should reduce the amount of memory allocate to the VM.