Hi everyone. I'm trying to make sense of the wacky CPU usage reporting I see in unRAID.
The problem is, the dashboard is showing 6%-8% overall CPU load (most of the time, 6%) while my one and only VM (Win10 x64) is sitting idle at the desktop. If I open the VM in VNC and look at task manager's details tab, System Idle Process is at 99%. This is as idle as Windows 10 gets.
top shows qemu-system-x86 using more than half a CPU core. This almost kinda sorta matches what the Dashboard is saying. But right there in the same top output, the line starting with %Cpu(s) shows 99.8% idle, 0.1% user space, 0.1% kernel space. These things are telling me different stories and I don't know what to make of it. I've also got a terminal there running htop, and its data is rather substantially different from Dashboard as well. Does anyone know why these numbers are so different?
This is a fresh install of unRAID 5 days ago. Currently I am not using this system for file storage at all except the minimum required to get the hypervisor enabled, which meant setting up a single disk in the array. I have one virtual machine configured. It is Windows 10 x64 and has one drive, a SATA SSD which is mapped directly to this VM (it was originally installed on bare metal, and can boot outside of unRAID). The VM has 14 cores (or hyperthreads) assigned to it -- that is all of them except for the first (CPU 0 - HT 8). I previously had assigned all but the last core (CPU 7 - HT 15), and the problem was no different.
So, I originally thought this was an issue with the VM configuration. I've searched for solutions and I've enabled the "hpet" timer in the VM's XML configuration, as is often recommended to fix high Win10 VM CPU usage.
<clock offset='localtime'>
<timer name='hpet' present='yes'/>
<timer name='hypervclock' present='yes'/>
</clock>
It did not help in any way I've been able to discern. I've also tried a common variant of this XML config which specifies "rtc" and "pit" timers, to no significant effect. If I reboot this VM, the qemu-system-x86 usage tends to settle below 10% in the top output for a while, but it will eventually jump back up to ~60-75%. Here is the rest of the VM's configuration: https://i.imgur.com/KqWGXmj.png
So, right now I can't decide if there is a serious efficiency problem with the current configuration, or if this is just something misleading like the CPU running at a low clock speed due to low demand, and consequently causing artificially high usage %.