This post discuss an issue involving Performance Monitor not properly showing the Logical Disk counters on a Cluster — upon selecting the cluster name in the Computer Name dialog in Perfmon, we were not able to view the Logical Disk counters. We instead saw the instances listed as “Harddiskvolume#” instead of the drive letter. Also, if the cluster was failed over, Perfmon would no longer monitor the logical disks. For all intents and purposes it appeared as though Perfmon lost connectivity with the disks. Obviously if you’re trying to get a baseline of your server performance or troubleshoot an issue, this is worrying behavior.