VM limits - CPU Limits

dpearceFL

CPU Limits has a #/# input. The second number appears to be the maximum number of vCPUs allocated. The first number appears to be the number of vCPUs the VM starts with.

Even if I hammer the CPU in the VM with "stress -c 6", lscpu only shows 1 CPU.

I can't find any documentation explaining this setting. What does this setting mean?

dpearceFL

BTW: Guest tools are installed in the VM.

mjtbrady

I couldn't find any documentation on this either. This is my understanding based on some experimenting. Someone correct me if I am wrong on any thing.

The first number is the number of vCPUs that the VM currenty has or will be started with. This can be changed while the VM is running. vCPUs will be hot plugged/unplugged. You can run top (not htop) while doing this to see the number of vCPUs changing and/or look at dmesg output. This can be changed manually in XO or by an XO job on a schedule.

The second number is the maximum number of vCPUs that the VM is allowed. This can only be changed when the VM is not running.

olivierlambert

That's correct: vCPU on boot and while the VM is running vs Max vCPU (hard limit, only editable while the VM is off).

dpearceFL

Thank you all for this wonderful information.