Last June, i have been on a customer site to deliver a Windows Server 2012 RDS VDI PoC platform. They were not prepared so they give me two very old servers (and i mean it). No matter, it’s a PoC. I told them to install Windows Server 2012 on these servers and to enable Hyper-V. After one day, they report me that they were unable to enable hyper-V due to a missing virtualization feature. mmmm, i checked the processor technical specifications, but i was unable to find details. I rebooted the server to check the BIOS, i didn’t find any window where i can enable or disable the Hardware-assisted virtualization feature. (The processor must meet the following requirements)
I took a moment of reflection : The processor does not support it or the BIOS needs update !!
I have no time for BIOS update (even if i have time, updating a 8 year old server BIOS is a nightmare), so i rapidly decide to check if the processor supports or not virtualization. I downloaded the Coreinfo tool made and tailored by the Mark Russinovich Windows ninja.
You need to just run the tool from a command line.
- The following is what i got when running the tool:
The legend is : ( * = present, – = not present)
You can see that the VMX feature is not present, VMX means “Supports Intel hardware-assisted virtualizaion”. Since my processor was an Intel one, i affirmed directly that this server is unfortunately useless in our case 😦
IMPORTANT NOTE : Hyper-V must be not enabled when making this verification, for a consistent result the Hypervisor should not be present. A ( – ) must follow the HYPERVISOR feature
- The following is the result of running Coreinfo in a Hyper-V production server. The tool indicates that the VMX feature is not present because the hypervisor is present
- The same case is when running the tool in a virtual machine : In the case of a Hyper-V virtual machine, the VMX feature is not inherited to the virtual processor of the VM, so the VMX feature is not present for a VM processor. But, we can’t say that the tool result is valid because the tool indicates that the Hypervisor is present. Results are not consistent.
- Finally, this is the result for a valid processor and result that supports virtualization
Don’t forget that Hyper-V (2008 R2 and 2012) needs in addition of the Virtualization feature, the Hardware-enforced Data Execution Prevention (DEP) feature. In the Intel case, it’s called NX bit. (NX in CoreInfo)
Note : For Hyper-V to run on a Windows 8 Pro or Enterprise machine, the processor must support SLAT feature. You can easily tape Coreinfo -v to display virtualization related features.