A memory guarantee is a percentage of virtual machine’s RAM that said VM is guaranteed to have.
Note
Important: The total memory guaranteed to all running virtual environments on the host must not exceed host’s physical RAM size. If starting a virtual environment with a memory guarantee would increase the total memory guarantee on the host beyond host’s physical RAM size, said virtual environment will not start. If setting a memory guarantee for a running virtual environment would increase the total memory guarantee on the host beyond host’s physical RAM size, said memory guarantee will not be set.
For virtual machines, the memory guarantee value is set to 40% by default. To change the default value, use the prlctl set --memguarantee command. For example:
# prlctl set MyVM --memguarantee 80
To revert to the default setting, run
# prlctl set MyVM --memguarantee auto
Note
Note: Virtual machines with memory guarantees can only be started with prlctl start. Starting such VMs differently (e.g., using virsh) will result in memory guarantees not being applied.
