When you create a VM in Windows Server 2012 R2 Hyper-V, you emulate all the components
that you typically find in a physical computer. When you virtualize memory, as discussed
in Objective 3.1, “Create and configure virtual machine settings,” you take a portion of the
physical memory in the computer and dedicate it to a VM. The same is true with hard disk
space. Hyper-V uses a specialized VHD format to package part of the space on a physical disk
and make it appear to the VM as though it is a physical hard disk drive.
When you create a new Generation 1 VM in Hyper-V, the wizard creates a virtual storage
subsystem that consists of two Integrated Drive Electronics (IDE) controllers and one Small
Computer Systems Interface (SCSI) controller. The IDE controllers host the VM’s system drive
and its DVD drive. Like their physical equivalents, each IDE controller can host two devices, so
you can create two additional virtual drives and add them to the system.
The SCSI controller in the default Generation 1 VM configuration is unpopulated, and you
can create additional drives and add them to that controller to provide the VM with additional
storage. In a Generation 2 VM, the system and DVD drives are connected to the default
SCSI controller and there is no IDE alternative.
In a VM of either generation, you can also create additional SCSI controllers and add drives
to them. By creating multiple drives and controllers, Hyper-V makes it possible to construct
virtual storage subsystems that emulate almost any physical storage solution you might
Following are points which will discuss in coming sections