The most common application for Hyper-V is server virtualization. That’s a use case that has almost obvious benefits. It’s not nearly as common to find desktop operating systems on the server platform (as opposed to Client Hyper-V or any of the various type 2 hypervisors). However, it is perfectly suited to the task.
The real question is: is desktop virtualization a solution to your problems? Such a solution is called a virtual desktop infrastructure (VDI). Creating and managing VDI are not trivial tasks in Hyper-V (or any other hypervisor) and can end in disaster if not properly planned. My goal with this article is to reach you during the contemplation phase where you’re trying to determine if VDI is worth tackling.
Here are 7 things to think about before even starting a pilot project:
1. Learn Your Letters
Searching on VDI is going to lead you into a morass of TLAs (three-letter acronyms) and FLAs that make it difficult to know what you’re reading. Let me help:
VDI: virtual desktop infrastructure
RDS: Remote Desktop Services — this is an umbrella term for VDI on Microsoft platforms
RDVH: Remote Desktop Virtualization Host — a Hyper-V host specialized to run Windows desktop operating systems as guests
RDSH: Remote Desktop Session Host — a Windows Server host that runs one operating system for many concurrent users
RDGW: Remote Desktop Gateway — a Windows Server system that funnels many users through a single keyhole so that they don’t need to directly access their desktops
RDCB or RDB: Remote Desktop Connection Broker: a Windows Server system responsible for directing user connections to their virtual desktop
RDWA or RDW: Remote Desktop Web Access: a Windows Server system that presents a web page that presents a user-friendly way to connect to a virtual desktop
2. VDI is Probably not Going to Save Any Money
We’re accustomed to server virtualization resulting in a cost savings. Those savings don’t translate into the VDI space at all. Here are some of the costs you’ll need to be prepared for to build a successful VDI deployment:
No hardware savings. Server virtualization enables hardware consolidation: many unique server deployments on much less hardware than physical deployments. It works very well because end users really don’t care how many towers are in the closet or how many rack slots are filled in the datacenter. They only care that their services are accessible. If you try telling 30 employees that they’re all going to have to share a single desktop computer on the same shift, you’ll get a noticeably less positive response. Even if they all have their own virtual desktop, they’ll still need unique devices to access them, and those cost money. It is possible to drive down the average cost of a virtual desktop to the $300 range, but once you add the remote device back in, you’re probably right back at the cost of a regular desktop (or higher).
Licensing is almost definitely more expensive. Licensing for VDI varies wildly. One thing is for certain: you won’t find anything quite like the guest virtualization rights for server when it comes to virtualized desktop operating systems. You can, of course, use non-Windows desktops in your virtual environment, but there are lots of asterisks and conditionals to go with that. I’m not going to go into them here, but I will say that I would likely not use Hyper-V as my VDI platform of choice if I weren’t going to use Windows desktops. So, you have to license the Windows environment for the virtual desktop, you have to license whatever operating system is on the device that your users access their virtual desktops from, and, depending on your particular VDI environment and licensing scheme, you probably have to license the fact that they’re connecting to a virtual desktop. You’re not going to come out ahead on licensing versus just buying a bunch of desktops or laptops with OEM Windows.
High availability isn’t cheap. Having one desktop go down is an annoyance. I don’t know anything about your organization, but I’m guessing that having a virtual desktop host crash and take 200 virtual desktops with it is likely to be categorized as “unacceptable”. You’re going to need to build up your hardware infrastructure to support your virtual desktop infrastructure, and that’s going to be expensive. You’re also going to have to buy enough licenses to cover every host.
You need more than Hyper-V on the server. Hyper-V alone does not a virtual desktop infrastructure make. You’re going to need at least one other fully-licensed Windows Server system and really, that’s not going to be enough.
Plan to pay for support. If you can follow the TechNet lab guides and build an environment that’s 100% acceptable for production, you’re ahead of the game. The tools are not robust and do not fare well once you start trying to make exceptions. VDI isn’t the most popular application of Microsoft technology, so there’s not as much publicly available information or as