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Windows Server 2012 R2 Hyper-V – Overview of Generation 2 VM’s

With the release of Windows Server 2012 R2 comes many great new features, including a improved virtual machine named generation 2.
Generation 2 virtual machines provide quite a few enhancements across the spectrum of Hyper-V VM technology. Perhaps most notable is the removal of legacy emulated hardware. Removal of the legacy network adapter, IDE controller, floppy controller, serial controller (COM ports), and PCI bus, results in a more efficient VM. You should see faster boot times, and quicker installations from .iso. How does a VM boot without these integral components? Where necessary, they have been replaced with software based versions.
Other enhancements include:

  • Replaced BIOS with UEFI (Unified Extensible Firmware Interface)
    • Faster boot times
    • Support for boot volumes up to 64TB (Uses GPT instead of MBR)
  • Enhanced Security
    • Smaller attack surface
    • Secure Boot – Prevents unauthorized firmware, drivers and OS from running during boot.
  • Expansion of data and boot disks while VM is running. Nice!
  • Complete reliance on VHDX file format resulting in much better performance (VHD’s are no longer supported).
  • Enhanced Session Mode
    • This allows device redirection and the ability to control display configuration when connected via the Virtual Machine Connection tool.

Some things to keep in mind with generation 2 machines:

  • Guest OS environments must be 64 bit, and only supports Server 2012 and Windows 8 or later.
  • Physical CD/DVD pass-through is no longer available. Although you can still attach physical disks to a VM, it is strongly discouraged due to the fact that any reliance on physical hardware makes live migration problematic.
  • Generation 2 is a feature of Server 2012 R2 and Windows 8.1. Keep this in mind if you try to live migrate a gen 2 machine to a Windows Server 2012 host. You can live migrate a generation 1 machine between 2012 R2 and Server 2012 hosts, but not generation 2.
  • You currently can’t officially convert a generation 1 machine to generation 2. Although there are PowerShell scripts which can make this happen, it isn’t supported by Microsoft. Hopefully, there will be a supported utility soon.
  • RemoteFX is not supported.

This is not an exhaustive list of the features of the new generation 2 virtual machine in Windows Server 2012 R2, but it is hopefully enough to get you interested. If you are ready for a deep dive, here is more information.
Next time you create a VM, choose generation 2.

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Glenn Martin

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