The hypervisor runs directly on the hardware and assigns different amounts of
resources to each virtual environment. These virtual environments can also be
referred to as partitions, because they are partitions of the underlying resource.
Because the management partition is not a true virtual machine (because not all
of its resources are virtualized) and it has privileged access, it is referred to as the
management partition or the parent partition. Although it can be confusing, it’s
also common to see the management partition referred to as the host because it is
the OS closest to the hardware and is directly installed on the server. Sometimes
virtual machines are referred to as child partitions or guest partitions.Windows Server 2008 Hyper-V Features
The initial version of Hyper-V provided a solid foundation for virtualization and a
fairly limited set of additional capabilities. As with all versions of Hyper-V, the
processors must support hardware-assisted virtualization (AMD-V or Intel VT) and
also Data Execution Prevention (DEP). Although Hyper-V is available only on 64 - bit
versions of Windows Server, it is possible to run both 32 - bit and 64 - bit operating
systems. The initial version of Hyper-V included the following key capabilities:
Up to 64 GB of memory per VM
Symmetric multiprocessing (SMP) VMs (up to four virtual CPUs [vCPUs] each).
However, the exact number differed depending on the guest operating system. For
example, four vCPUs were supported on Windows Server 2008 SP 2 guests, but
only two were on Windows Server 2003 SP 2. The full list is available at:
http://technet.microsoft.com/en-us/library/cc 794868 (v=ws. 10 ).aspx
Virtual Hard Disk (VHD) format for virtualized storage up to 2 TB in size with
multiple VHDs supported for each VM on either a virtual IDE controller or a
virtual SCSI controller. VMs had to be booted from a VHD attached to a virtual IDE
controller, but data VHDs could be connected to a virtual SCSI controller with
higher performance through the virtual SCSI controller. Only 4 devices could be
connected to the IDE controller ( 2 to each of the 2 IDE controllers), while each of
the 4 virtual SCSI controllers supported up to 64 devices, each allowing up to 256
VHDs attached via the virtual SCSI.
Leveraged failover clustering for high availability
Ability to move virtual machines between hosts in a cluster with minimal
downtime using quick migration. Quick migration worked by pausing the virtual
machine and saving the device, processor, and memory content to a file on the
cluster storage. It then moved that storage to another host in the cluster, reading
the device, processor, and memory content into a newly staged virtual machine on
the target and starting it. Depending on the amount of memory in the virtual
machine, this may have meant minutes of downtime and the definite disconnect of
any TCP connections. This was one of the biggest weaknesses of the Windows