Hyper-V 2012 R2 Generation 1 vs Generation 2 VMs


In earlier versions of Hyper-V, It was not possible to boot a virtual machine from a SCSI virtual hard drive .It was also not possible to copy files from host to virtual machine without having a network connection in the virtual machine .

In virtual machines running 2012 and earlier, the Hyper-V BIOS only supported legacy drives such as IDE controller and legacy network cards.

Starting with windows server 2012 R2, there are two types of Hyper-V boot architectures available.

i.e., Hyper-V BIOS and Hyper v unified extensible firmware interface BIOS, virtual machine created with Generation 1 supports legacy drivers and uses Hyper-V BIOS-based architecture. Hyper-V BIOS-based virtual machines can only initialize IDE Controller for Operating System to initialize a file system, which is shown in the below image

On the other hand, a virtual machine created with Generation 2 supports  UEFI-based architecture, in which a subset of Integration Service components has been included to allow SCSI Controller to initialize before the Operating System starts loading. This is shown in the above image:

Benefits of Generation 2 VMS

  1. Boot from SCSI virtual hard drive
  2. PXE boot option
  3. Secure Boot
  4. Faster boot time and installation for guest operating system
  5. Only 64 bit operating systems
  6. VHDX boot volume can support up to 64 TB

An absolute beginner’s guide to Microsoft Hyper-V

Virtualization is the creation of a virtual version of an IT environment which includes an operating system, a storage device, a network device, etc. The Hypervisor is the processor-specific virtualization platform that can host multiple virtual machines (VMs) that are isolated from each other but share the underlying hardware resources by visualizing the processors, memory, and I/O devices.

Microsoft introduced Hyper-V as a virtualization platform in 2008 and it continued to release new Hyper-V versions with new windows server versions. So far there are a total of four versions including windows server 2012 R2,Windows server 2012,windows server 2008 R2 and windows server 2008( Not including windows server 2016 now).

Hyper-V is a hybrid Hypervisor which is installed from operating system, however doing the installation it redesigns the OS architecture.



The magical transformation, when you add Hyper-V role in windows server *

                                           You first install windows server operating system at this point there is no hypervisor. When you enable Hyper-V role windows will install all required software components like VMBus and VSP but not the hypervisor. Instead windows installs the device driver Hvboot.sys, which will load the actual hypervisor on the next boot. This can be either %system root%system 32%Hvax64.exe for AMD processor %systemroot%system32%Hvix64.exe .These files are very small in size. Once loaded, the hypervisor used the virtualization extension of the CPU to inset as a ring -1 process, taking over the control of the hardware. It proceeds to load the windows server 2012  kernel to the parent partition, prepared with VMBus and VSP. Here your Hyper-V is ready to start .

Hyper-V is a great option for consolidating your server hardware,If you want to experiment with Hyper-V and you can try doing experiments with your windows 10 workstation.