vSphere 5.1 hot cloning failure

We have run into this issue a few times after migrating servers from vSphere 4.x to vSphere 5.x. When trying to hot clone a vm the process fails and generates an error as seen in the screenshot below. We have seen this on Windows 2008 servers and Windows 7 clients.

Luckily there is a trusty KB article from VMware that helps solve this issue. The KB article can be found here.

In short here is all you need to do.

To enable Windows 2008 virtual machine application-consistent quiescing:

1. Open the VMware vSphere Client, and log into a vCenter Server.
2. Select Virtual Machines and Templates and click the Virtual Machines tab.
3. Locate the Windows 2008 virtual machine for which you are enabling the disk UUID attribute, and power off the virtual machine.
4. After power-off, right-click the virtual machine, and choose Edit Settings.
5. Click the Options tab, and select the General entry in the settings column (under the Advanced entry).
6. Click Configuration Parameters.
7. Click Add Row.
8. In the Name column, enter disk.EnableUUID.
9. In the Value column, enter TRUE.
10. Click OK and click Save.
11. Power on the virtual machine.

Enjoy!