ESX: VM’s with wrong CPUID mask show bluescreen after 5.X > 6.0

This is due the NX/CD flag CPUID mask set on machines. Esp. we had seen this on Server 2012R2 which were installed on ESX5.0/5.X and the flag had to be set so machines where running. Be sure to capture this in advance or in time because the SRV2012 will start in Recover Mode at some point.

2008R2 > Bluescreen

2012R2 > Boots into Recovery Console

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2014835

To resolve this issue, reset the CPUID Mask settings on the affected virtual machine.

To reset the CPUID Mask settings:

1. Using the vSphere Client, connect to vCenter Server and locate the affected virtual machine.
2. Power off the virtual machine.
3. Right-click the virtual machine and click Edit Settings > Options > CPUID Mask > Advanced.
4. Click Reset All to Default to reset the CPUID Mask.
5. Click OK > OK, then power on the virtual machine.
6. The virtual machine now shows the correct EVC mode.

Note: If these steps do not resolve the issue, upgrade the virtual machine's virtual hardware to the latest version. For more information, see Upgrading a virtual machine to the latest hardware version (1010675).

Here is the relevant Link where the Flag was set:

http://www.butsch.ch/post/Server-2012R2-VMware-50X-Blue-screenBSOD-Event-41-CPUID-Mask-Flag.aspx

Here is a script to report the flags on all machines:

http://www.lucd.info/2010/05/13/nxxd-flag-setting-report/