ESXi - esxtop shows high %RDY value fo service "system"

[MarinPosavec]

We have one ESXi on vCenter (ver. 6.7) host with cca. 35 Virtual Machines (Windows 10 / VDI / Horizon View / PCoIP). On this host, we have 5 additional VMs (WinSrv2016, vCenter Virtual Appliance, vSAN VM...).

For all Windows 10 VMs, we have 2 vCPUs (2 Cores per Socket / 1 Socket), and CPU Ready time in vCenter is ok (Average value is "52" for both vCPUs together). Also, on this host we have vGPU (Nvidia Tesla M10).

When I check performance with esxtop (SSH), for all Windows 10 VMs %RDY value is bellow "1.00". What bothers me is %RDY value for service "system" which is all of the time cca. "2000.00". In attachment is screenshot where you can see this. Is this normal, or what should we check in order to fix it?

[vbondzio]

Hi Marin,

the idle worlds (one per PCPU) are ready when they are not running. They used to be in a separate group next to system but with 6.5, they were moved into it. Expand ('e') System (1) and see for yourself. No reason to worry 🙂

Cheers,

Valentin

[nitvat]

Valentin​ Still why the CPU ready for 'system' is high. Does it impact performance of ESXi host. I have seen a case where we have only 2 VM running on an ESXi host. VM Utilization is low, still I see notification of ESXi host reaching at 100% CPU Utilization. System % Ready is touching 2000 at sometime. It is for 6.7 U1.

CPU load is 1.4  1.6  1.8.

[vbondzio]

Hi @nitvat , check out the 2nd part of: https://www.vmworld.com/en/video-library/video-landing.html?sessionid=1589484575728001Zb6J

I explain it there.