A company runs several instances of multi-threaded application that requires virtual machine to be configured with multiple vCPUs.

Which metric is checked to determine if CPU contention exists on an ESXi 5.x host?

A.
%RUN

B.
%WAIT

C.
%USED

D.
%RDY

Explanation:

http://communities.vmware.com/docs/DOC-9279

“%WAIT”
The percentage of time the world spent in wait state.

This %WAIT is the total wait time. I.e., the world is waiting for some VMKernel resource. This wait time includes I/O wait time, idle time and among other resources. Idle time is presented as %IDLE.

“%RDY”
The percentage of time the world was ready to run.

A world in a run queue is waiting for CPU scheduler to let it run on a PCPU. %RDY accounts the percentage of this time. So, it is always smaller than 100%.

+Q: How do I know CPU resource is under contention?+
+A: %RDY is a main indicator. But, it is not sufficient by itself.+