Windows Server 2012 R2 Gen 2 VMs by Richard Qi

26 Aug 2013

In Windows Server 2012 R2, you can create a new type of VMs called Generation 2 VMs.

Gen 2 VMs will give you several benefits including:

Emulated devices have been removed
Allows for boots from virtual SCSI
You can boot from synthetic network adapters
Boot from UEFI instead of BIOS
UEFI secure boot is enable
You can run Gen1 and Gen2 VMs side by side
Enable Enhanced Session Mode

Why Gen 2 VMs?

Historically OSs didn’t natively understand virtualization, and in the case of Hyper-V, could not just use the VMbus. This is why there are emulated IDE controllers, legacy network adapters, emulated BIOS, COM & LPT ports, keyboard or mouse PS/2 connections, floppy drives, and other system devices such as PCI to ISA bridge. All of these emulated type devices include the requirement to boot from an IDE controller, because the assumption was that OSs weren’t natively virtual aware.

Today, even Linux now are natively virtualization aware. Therefore in Windows Server 2012 R2 Hyper-V, a new Gen 2 VM is available that removes all the legacy, emulated hardware and provides a UEFI environment that supports 64-bit OSs that are Windows 8 and Windows 2012 or later. Generation 2 VMs can boot from the SCSI bus and from the synthetic network device.

Where do you see the differences?

When you boot into a Gen 2 VM, you will see Hyper-V instead of the Windows Logo.

Enable ‘Enhanced Session Mode’ under Hyper-V Settings.

It functions exactly like a RDP Session. You can adjust the display settings and also redirect other devices to the VM including USB devices

You can also change the boot order for Gen 2 VMs under the firmware option

Compare the device cialis 20mg manager of Gen 1 VM vs. Gen 2 VM, you will notice Gen 1 VM on the left is PCI Bus Connection and Gen 2 VM on the right is VM bus.

How to migrate from Gen 1 VM to Gen 2 VM?

As Gen 2 VMs use UEFI, it has no direct migrate path from Gen 1 VM to Gen 2 VM. Niklas Akerlund has blogged about how he has successfully converted a Gen1 VM into a Gen2 VM using Double-Take Move, which is a third party software.