Windows 8 is about to hit shelves, and one of the features that's creating buzz is Client Hyper-V, which desktop virtualization pros could potentially use to deploy a single Windows image to any desktop hardware
Client Hyper-V is Microsoft's client-side implementation of the Hyper-V hypervisor that's been used in Windows Server since 2008. In the desktop virtualization world, our interest is piqued because it's a new Type 1 client hypervisor on the market that could be used for desktop management. (Type 1 hypervisors run directly on the hardware, whereas Type 2 hypervisors rely on an underlying OS to connect virtual machines to the hardware. VMware Workstation is a Type 2 hypervisor, while ESX is Type 1.)
Companies including Citrix (which got a better alternative to XenClient when it acquired Virtual Computer), VMware, Virtual Bridges and Mokafive all have client hypervisor products that do this in one form or another. But what can Client Hyper-V really do for VDI admins?
Who needs Client Hyper-V?
As we get our hands on Windows 8, we've come to see that Client Hyper-V is targeted not at desktop management, but at IT pros looking for an extra virtual machine (VM) or two on their computers. Many IT pros have tried to install Windows Server on a laptop to get a base OS they can use, plus several VMs on which they can install different servers and services, only to be disappointed that the server version of Hyper-V lacked the functionality needed on desktops and laptops.
For instance, the server-based Hyper-V wasn't aware of power management, lid closures, sleep mode, and several other things that aren't found on servers. Because of this, people either put up with it by shutting everything down each time they closed the lid on their computer (closing the lid on a laptop running Windows Server does nothing -- it would still run) or by skipping Hyper-V altogether and going with a Type 2 hypervisor, such as VMware Workstation.
More on client hypervisors
Guide to client hypervisors
Why you may need a client hypervisor
Is XenClient better than XenDesktop for VDI?
What about the desktop?
You can see how a client-aware hypervisor from Microsoft would be helpful to that community, but what about the desktop virtualization crowd? In Windows 7, Microsoft included XP Mode, which allowed you to run problematic or legacy Windows apps in a Windows XP virtual machine if they would not run in Windows 7. The biggest problems were that XP Mode was relatively unmanaged, and it ran on a Type 2 hypervisor: Microsoft Virtual PC. To address the manageability, Microsoft introduced MED-V, which allowed organizations to manage the VMs to some extent.
The announcement of Client Hyper-V gave us some hope that Microsoft was addressing the second issue with a high-performance, low-overhead solution that could be managed via System Center. Best of all, it seemed it could be deployed across organizations that want the benefits of a client hypervisor for desktop management.
Uses for Client Hyper-V
In reality, Microsoft missed the boat by targeting only server virtualization pros. Instead of creating a de facto desktop virtualization method that every organization had available to them, they focused it specifically on a niche group of users that make up a ridiculously small percentage of the Windows install base.
So what can we use Client Hyper-V for? It can be used to replace XP mode, especially since that was unmanaged from the start. Client Hyper-V would provide a better experience for Windows XP and the applications without costing as much overhead as Virtual PC does with XP Mode. Of course, you have to go to Windows 8 to do that, and that's not high on many companies' lists.
Client Hyper-V could also serve as a migration tool, both for server virtualization and VDI admins. Since it's the same Hyper-V that runs on Windows Server 2012, the VMs are 100% portable. That means admins can create VMs at their desk, then migrate them into the data center when they're ready. Organizations probably already have a test server for this, though, so this probably isn't a broadly viable use.
The same could be said for VDI scenarios that use Windows Server 2012. You could create VMs on the client side and move them into VDI. Perhaps there's an angle where users only use Client Hyper-V as their Windows desktop for a while, and that's how you build out or test the image before deploying it full scale. Again, it's kind of unnecessary, but Microsoft hasn't given us much to work with.
With the lack of interest we're seeing in terms of deploying Windows 8, Microsoft could help drive early adoption by adding management components to Client Hyper-V. In the meantime, the door is left open for third parties to make centralized management tools for VMs running on Client Hyper-V. Citrix is invested in Xen as their client hypervisor of choice, but Xen and Hyper-V have such similar architectures, perhaps Citrix will step up and offer to manage Client Hyper-V VMs. Dell Quest is very tight with Microsoft, so that could also be on their radar.
There's plenty of room for others, too, but Microsoft could (and should) just do it themselves.
This was first published in September 2012