Monitoring software shows incorrect system uptime for Windows 2008 R2 or later on hardware version 10

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• Third-party monitoring software displays an incorrect uptime for a virtual hardware 10 virtual machine.
• The guest operating system is Windows Server 2008 R2 / Windows 7 or later.

Environment

• VMware vSphere ESXi 5.5
• VMware vCenter Server 5.5.x

Cause

VMware virtual hardware 10, does not reset the TSC CPU registers which is read by third-party products as a QueryPerformanceCounter but leaves them unmodified during a soft-restart. This is by design and is an expected behavior.

With the addition of virtual hardware 10 in vSphere 5.5, a different hardware clock mechanism was introduced for up-to-date support with the Microsoft Server Virtualization Validation Program. For more information, see VMware Blog article: Microsoft Operating System Time Sources and Virtual Hardware 10.

Resolution

This feature is by design in VMware virtual hardware version 10 and is in compliance with the Microsoft Server Virtualization Validation Program (SVVP) at the time of the initial release of this hardware version.

If the third-party software relies on the QueryPerformanceCounter to reset during a soft-reboot, add the monitor_control.enable_softResetClearTSC = TRUE to the virtual machine's advanced configuration.

To add the monitor_control.enable_softResetClearTSC = TRUE to the virtual machines advanced configuration in the vSphere Web Client:

1. Log in to the vSphere Web Client.
2. Ensure that the virtual machine has been shutdown and is powered off.
3. Right-click on the virtual machine.
4. Click Edit Settings to open the Virtual Machine Edit Settings window.
5. Click VM Options.
6. From the list on the left, expand the Advanced option.
7. Click Edit Configuration.
8. Click Add Row.
9. Type monitor_control.enable_softResetClearTSC in the new Name column.
10. Type true in the new Value column.
11. Click OK to save the change to the virtual machine.