Understanding %WAIT CPU Counter

[Valley911]

Hey All,

I was doing a little digging around in resxtop on our ESXi 4.1 U1 hosts and noticed on the cpu screen that all of the VM's on a given host had %WAIT times in the hundreds (anywhere from 200 to 400). We have received no complaints of the VM's running slowly and the %RDY time was below 1 on all VM's. To make sure there wasn't an I/O issues I checked both the disk and network performance and all looks good there. The ESX host in question has 8 logical cores (dual quad cores) and is currently running 9 single vCPU VM's. I guess the question is, does a high %WAIT time represent an issue in our enviroment?

Thanks for any help,

-Jason

[Troy_Clavell · Accepted solution]

I think the below document explains it best

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

[Valley911]

Troy,

Thank you for the post. After reading the section on %WAIT in that document I have a better understanding of that counter.

-Jason