As a reminder to everyone, use the perf counter “\Hyper-V Hypervisor Logical Processor(_Total)\% Total Run Time” to measure CPU in a Hyper-V environment.

If you are trying to measure CPU utilization in a Hyper-V environment and are a bit frustrated as to why the numbers don’t match up, then read the excerpt below. I spent a month with the BizTalk Product Team doing analysis of BizTalk in a Hyper-V environment. We had the virtual computers (guest) running at 100% CPU, yet Task Manager on the host computer (root partition) was about 1% on all of the CPUs.

Excerpt from http://msdn.microsoft.com/en-us/library/cc768535.aspx

Measure overall processor utilization of the Hyper-V environment using Hyper-V performance monitor counters – For purposes of measuring processor utilization, the host operating system is logically viewed as just another guest operating system. Therefore, the “\Processor(*)\% Processor Time” monitor counter measures the processor utilization of the host operating system only. To measure total physical processor utilization of the host operating system and all guest operating systems, use the “\Hyper-V Hypervisor Logical Processor(_Total)\% Total Run Time” performance monitor counter. This counter measures the total percentage of time spent by the processor running the both the host operating system and all guest operating systems.

Also, the PAL tool has a threshold file for Hyper-V with this information in it. http://www.codeplex.com/PAL

BizTalk Server 2006 R2 Hyper-V Guide (Full Guide)

http://msdn.microsoft.com/en-us/library/cc768518.aspx

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