High CPU load of the process KVM

[David G.]

Hello, I'm new to the forum and completely new to the topic of Proxmox.
Please excuse any terms that may be incorrect. Also related to my English.

I set up proxmox with 4 small machines.
According to the dashboard my CPU usage is between 3% and 6%.
However, this is much higher via the shell on the host. The process with the PID 1646 kvm alone always requires 30% to 40%. Is that normal? You can also notice this in the high energy requirements of the server.

The processor is an I3 12100.

root@pve:~# top
top - 22:25:27 up 15:00,  1 user,  load average: 0.50, 0.50,  Tasks: 302 total,   2 running, 300 sleeping,   0 stopped,   0 %Cpu(s):  4.1 us,  0.6 sy,  0.0 ni, 91.5 id,  0.0 wa,  0.0 hi MiB Mem :  31888.0 total,   6159.6 free,  25455.7 used,    71 MiB Swap:   8192.0 total,   8192.0 free,      0.0 used.   643     PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM
   1646 root      20   0 9622132   5.6g  19572 S  33.9  18.1
   4695 root      20   0 9230360   7.9g  10112 S   4.0  25.3
   1473 root      20   0  151960 103128  12416 S   1.0   0.3     1699 root      20   0       0      0      0 S   0.7   0.0
   1543 root      20   0 2178184   1.1g  19268 S   0.3   3.4
 880743 root      20   0       0      0      0 I   0.3   0.0
 884607 www-data  20   0  235524 139932   9216 S   0.3   0.4
      1 root      20   0  168564  12376   8920 S   0.0   0.0
      2 root      20   0       0      0      0 S   0.0   0.0

root@pve:~# ps -e
    PID TTY TIME CMD
....
   1646 ? 04:24:24 kvm
....

 

[leesteken]

Please note that the P{roxmox GUI uses a scale where 100% is all 8 CPUs at 100% while top uses a scale where 100% is 1 CPU at 100% (full system usage is 800%). It's not surprising that there is a difference of a factor of eight (and some rounding). There is some overhead in the kvm processes because it needs to emulate/para-virtualize things like disk and network controllers.