I've just added some Windows 7 virtual machines to an existing VMWare vSphere 5.1 cluster. The hosts and vCenter are 5.1 with current updates via Update Manager.

Looking at the vSphere client performance graphs, I see random sustained jumps in the guest CPU utilization. These are new VM's with no software installed. They were trimmed-down and optimized according to this guide. The VMWare guest tools are installed.

The systems are idle as this is happening. There's no corresponding activity within the guest's Task Manager or Performance chart.

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Any thoughts on what the issue could be? I suspect a guest tools/version interaction, but a root cause would be helpful.

  • Have you caught anything in task manager within the VMs when it's happening? – Shane Madden Nov 19 '12 at 6:19
  • Yeah, the task manager is flat, even while the vCenter chart shows 100% utilization. – ewwhite Nov 19 '12 at 6:22
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    Is anyone logged in while this is happening? I've noticed this bug causing some similar funkiness on my vSphere5.1 VMs. Turning off logging for VMTools did correct it for me, though I'm not exactly thrilled with that "fix." – HopelessN00b Nov 19 '12 at 7:02
  • Nobody logged-in. These are freshly-created VMs. – ewwhite Nov 19 '12 at 7:09
  • Hi mate, if you check the host directly, is this spike showing to the same degree? – Rqomey Nov 19 '12 at 9:18

Use esxtop to check for another world (log into ssh on host and run esxtop). See if you can isolate what is using the resources. If you are running an appliance such as vShield (or there are other situations) you may have a second world created which would be running up the resource usage.

Is procmon reporting any high usage tasks on the host?

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