VMs and Windows Performance Monitor

[AtlasAdmin]

In the next few days I will need to prepare load testing on a clients

existing physical environment and newly created virtual environment to

compare system performance under load.

After reading up on the subject, my understanding of various online

documents has shown that we cannot rely accurately on data captured

from within the virtual machines using Windows Performance Monitor

because of a skewing of time within the virtual machine.

Could anyone confirm that using Windows performance Monitor from a

remote physical machine to capture data from the virtual machine

machine overcome this problem?

Thanks in advance,

Paul

[AWo]

The inaccuracy is due to the inconsistent increase of the timers within the guest, the guest doesn't own the CPU all the time and has no clue what is happening on the host. To monitor the load rely on the host based tools. With ESX that is esxtop or VirtualCenter.

Reading the performance from external hosts may even not be accurate when they "just" read counters generated in the guest, like WMI.

Check KB 2032, 1077 and 1730.

AWo
VCP / VMware vEXPERT 2009

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