How Hyper-V Works In Windows 8?

In a September 7 blog post "Bringing Hyper-V to Windows 8" authored by Mathew John, program manager on Hyper-V team, talked about how the company will support virtualization on the Windows "client" OS.In the post John notes, Microsoft's licensing rules around HyperV are not changing just because the technology will be available on PCs. "You […]

In a September 7 blog post "Bringing Hyper-V to Windows 8" authored by Mathew John, program manager on Hyper-V team, talked about how the company will support virtualization on the Windows "client" OS.

In the post John notes, Microsoft's licensing rules around HyperV are not changing just because the technology will be available on PCs. "You will still need to license any operating systems you use in the VMs."

John wrties, that "by bringing Hyper-V from Windows Server to Windows Client, we were able to provide a robust virtualization technology designed for the scalability, security, reliability, and performance needs of most data centers. With Hyper-V, developers and IT professionals can now build a more efficient and cost-effective environment for using and testing across multiple machines."

He said, "In building Windows 8 we worked to enable Hyper-V, the machine virtualization technology that has been part of the last 2 releases of Windows Server, to function on the client OS as well."

"In brief, Hyper-V lets you run more than one 32-bit or 64-bit x86 operating system at the same time on the same computer. Instead of working directly with the computer's hardware, the operating systems run inside of a virtual machine (VM)."

As you can see in the video demo below, "creating an external network switch is as simple as selecting a physical network adapter (NIC) from a drop-down list and clicking OK. This already worked well for Windows Server Hyper-V, but to have similar results in Windows 8, we needed to get it working with wireless NICs, a new challenge," explained John.

He explains that "we used the Microsoft Bridging solution, which implements ARP proxying (for IPv4) and Neighbor Discovery proxying (for IPv6) to replace the virtual NICs' MAC address with the WiFi adapter's MAC address for outgoing packets. The bridge maintains an internal mapping between the virtual NIC's IP address and its MAC address to ensure that the packets coming from the external world are sent to the appropriate virtual NIC."

Hyper-V integrates the bridge as part of creating the virtual switch such that when you create an external virtual switch using a WiFi adapter, Hyper-V will:

  1. Create a single adapter bridge connected to the WiFi adapter
  2. Create the external virtual switch
  3. Bind the external virtual switch to use the bridge, instead of the WiFi adapter directly

In this model, Ethernet switching still happens in the virtual switch, and MAC translation occurs in the bridge. For the end user who is creating an external network, the workflow is the same whether you select a wired or a wireless NIC.

On a side note, Paul Thurrott in a tweet raised the question about the quotes used in the blog post title. That's true Microsoft official have not use quotes unitl now, and this is the the firt time. To which, Ed Bott added, Microsoft didn’t use this convention when referring to Windows 7. Does that means, Windows 8 is just the codename!!

MJF speculates the final name of Windows Server 8 will be Windows Server 2012 — or 2013 if it is released to manufacturing very late in the year.