In Hyper-V, is the Root Partition a Virtual Machine?
OK, so I couldn't help myself! For some time now I have been trying to autocorrect people when they say the Root Partition is a virtual machine.
If the Root Partition was a virtual machine then where is its associated Worker Process???
Well a colleague of mine got to ask a Virtualisation PM (Ben Armstrong) the question while at the MVP summit. Here is a snippet:
Today Ben Armstrong a programme manager of the Hyper-V product group took the time to answer the question for me. This question and its answer really has no practical application or significance but it does help clarify some Hyper-V terms.
So Hyper-V has the root partition, which the hypervisor allows direct access to the hardware devices such as the NICs, and then there are the child partitions where guest VMs run.
Both a virtual machine and the root partition have their CPU and memory resources allocated and managed by the hypervisor. But a VM access all IO devices (NICs, disk drives and so on) either via the VMbus or emulation though the hypervisor. To do IO a VM must use the virtualisation services provided by the root partition. The synthetic devices in the guest VMs or the Hypervisor (on behalf of the guest VM) use the VMbus to redirect a VMs IO requests to the root partition.
So because the root partition does not use its own virtualisation services to access hardware devices but is allowed by the hypervisor to access the IO hardware devices directly, by definition, the root partition is NOT a VM.
Check the blog out at http://cid-39d7e872cb035259.spaces.live.com/blog/
Patrick Lownds