Generation 2 VMs – The new type of virtual machine.

With the release if Microsoft Windows Server 2012 R2 there will be two options when you come to create your VMs – Generation 1 or Generation 2 VMs.

Generation 1 VMs are the ones you have been use to since the release of Hyper-v with Windows Server 2008. With Windows Server 2012 R2 you will have the option of choosing a generation 2 VM, this 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#
  • No performance improvements on Gen2 VMs. Having said that booting is around 20% faster and OS install can be 50% faster.

If you look at a Gen1 vs. a Gen2 settings screen below (Gen1 is on the left with Gen2 on the right) for Hyper-V you will notice a lot of the options you are use to appear to be ‘missing’. This is because things such as the IDE controllers are no longer needed – you can use the SCSI controller to boot! Other options that are no longer needed for Gen2 is the COM and Floppy ports. Also there are no longer any emulated devices.

Gen2 machines now fully support UEFI rather than the traditional BIOS – you can see on the Gen1 settings on the left you have the usual ‘BIOS’ options and on the Gen2 you have ‘Firmware’. With UEFI secure boot has been enabled by default to protect your VMs during the boot process.

One thing that will please a huge number of Hyper-v users will be the ability to do full PXE booting – you no longer need to use the emulated network adaptor (emulated network no longer exists) you have the full network bandwidth.


As mentioned above, Hyper-v Gen2 machines no longer need emulated devices. You can see this below with the device manager. Again Gen1 is on the left with Gen2 on the right. The Gen1 clearly shows the emulated devices under the PCI to ISA bridge (Microsoft used the ISA bridge to prevent the need to consider Plug n Play).  With the Gen2 device manager you can see all the devices are running through the native VM Bus.


Finally one feature that I have been waiting for since working with Hyper-v although very trivial is copy and paste. Hyper-v will now allow you to copy and paste text and even files both ways between VMs (just like with RDP). Sound is also now available within the VM – play a video in the VM and hear the sound on the local machine.

As always though there are some gotta’s with this new technology. You must be running at least Windows Server 2012 or Windows 8 x64 operating systems and once you have made the decision on the generation of VM you want to use you can’t change it.

Due to some of these limitations Microsoft have stated they are aware people will need Generation1 VMs for quite some time so these traditional virtual machines you are use to and all the settings that go along with them are not going away anytime soon. Having said that if you are using Windows Server 2012 (R2) or Windows 8 (.1) Generation 2 is worth a look.