After you install ESXi 5.1 and boot the system for the first time, the ESXi 5.1 host might log vim.PerformanceManager error message similar to the following to the hostd log file:
Error while loading stats depot: "FileIO error: Could not find file : /var/lib/vmware/hostd/stats/hostAgentStats.idMap". Possible file corruption!
This is a known issue in ESXi 5.1. You can ignore this error message during first boot after installation
Based on VMware KB 2036086