Scott Drummonds on Virtualization

Inaccuracy of In-guest Performance Counters


Every couple of months I receive a request for an explanation as to why performance counters in a virtual machine cannot be trusted.  While it is unfairly cynical to say that in-guest counters are never right, accurate capacity management and troubleshooting should rely on the counters provided by vSphere in either vCenter or esxtop.  The explanation is too short to merit a white paper but I hope a blog article will serve as the authoritative comment on the subject.

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