3 Replies Latest reply on Oct 27, 2011 6:14 AM by edgrigson

    High CPU ready time

    tomaddox Hot Shot

      Hi, everyone,


      I have just replaced all of my ESX hosts in a cluster with ESXi 4.1 hosts of a much newer generation, and I am still seeing a significant amount of CPU ready time on many of the the VMs in that cluster. I'll run through the configuration information and see if anything jumps out:


      # of hosts: 5

      # of CPU cores per host: 24 (2x Opteron 6176 per host)

      # of CPU cores per cluster: 120

      RAM per host: 256 GB

      RAM per cluster 1.25 TB

      # of VMs powered on in cluster: 289


      The hosts are HP BL465G7 blade servers.


      Most of the VMs in this cluster are virtual desktops with the following configuration:


      Guest OS: Windows XP

      RAM: 1-2 GB

      vCPUs: 1

      VMware Tools: yes, up to date

      VM Hardware version: 7 (mostly)


      CPU utilization is pretty low in terms of MHz, under 25% across the board. I am seeing excursions over 20% CPU ready time in some cases, but there's no indication that the hosts are overloaded at those times.


      Any thoughts?