Esxi CPU usage dropps suddenly, and VMs performance are affected

Products

• VMware vSphere ESXi

Issue/Introduction

End user reported that on one of the Esxi host, the Esxi host CPU usage dropped suddenly:

Environment

Esxi 7.0.x

Esxi 8.0.x

 

Cause

1)  Check power management settings in BIOS :

In physical server BIOS, the system profile setting is: Performance by Watt (OS) , it means : OS( Esxi ) handles the power management.

2) 

In vCenter Web GUI, choose the Esxi host, in right pane, click on 'Overview'  under the 'Hardware' section.

Ensure the 'Active policy' in 'Power Management' is 'High performance'

3) ssh to Esxi

Run esxtop, press p, it shows the C state and P state , we can see most of the CPU cores in P13 state, this is abnormal. 

When it is 'high performance', the P stat should be  P0, not P13.

 

 

 

 

    C0=50.0%  C1=50.0%  C2=0.0%

    P0=98.3%  P1=0.0%  P2=0.0%  P3=0.0%  P4=0.0%  P5=0.0%  P6=0.0%  P7=0.0%  P8=0.0%  P9=0.0%  P10=0.0%  P11=0.0%  P12=0.0%  P13=1.7%  P14=0.0%  P15=0.0%

 

 

Resolution

1) It should be an issue with the physical CPU core .Please contact hardware vendor to check it.

2) For this case,  cold shutdown Esxi host, then power on the Esxi,  CPU  P states  are back to P0, monitor the Esxi host.