What is VDI?

25. May, 2009 0 Comments

Since this is my first blog entry relating to VDI, it makes sense to me that I should go over the basics and talk about what VDI is. This is especially important if you’ve never heard of VDI before, and for those of you who are not new to it, this can serve as a review. Let’s start with a definition that I found at http://en.wikipedia.org/wiki/Desktop_Virtualization:

“Virtual desktop infrastructure (VDI) is a server-centric computing model that borrows from the traditional thin-client model but is designed to give system administrators and end-users the best of both worlds: the ability to host and centrally manage desktop virtual machines in the data center while giving end users a full PC desktop experience.”
Ok, that’s great – but what does all that mean to you? Before we get too far into the definition, let me say that VDI, at least in this blog, is a generic acronym. Some other vendors (cough – Microsoft – cough) use the term HVD, for Hosted Virtual Desktops. However, this blog as a whole will attempt to stay vendor-independent and use the generic terms, unless we’re talking specifically about a product. Now that we’ve got that out of the way, let’s clarify the definition by talking about some of the benefits of VDI and what you will get out of it. In today’s computing environment, many companies are concerned with the sometimes delicate balance of cost vs. security. On the cost side of things, the current state of the economy dictates that costs stay low and spending stays down, or the “dollar” cost. Another less-common cost consideration is what I’m calling the “experience” value – the relative ease-of-use of a given solution for a typical end-user. We want this value to be high, indicating a highly usable system. Then of course there’s the security side of the equation. We all want to keep our data private and easily accessible, but only to those that need it. So how can you have a solution that:
a) Keeps the “dollar” costs down,
b) Maximizes the “experience” value,
c) And maintains data security?
If you put enough money into security (high “dollar” cost), you’ll get a generally secure system, but high security “dollars” do not always equal high security. Sometimes that high security system also comes with a hit on the “experience” value, since secure systems can be difficult to use. Or, if you design a system that’s highly usable, it may not be very secure or cost effective. And of course if you don’t spend any money at all, nothing will change. Data won’t be any more secure, and Users’ experience won’t change.

I believe that VDI can address these three areas of concern. VDI can help reduce costs by reducing management, administrative, and resource overhead, while at the same time increasing the user’s experience and securing data inside the datacenter. How does this work? Allow me to elaborate. With traditional computing, a user has a desktop or laptop computer, which uses local resources (CPU & Memory) to run applications. These applications are installed either by a person or a process, requiring time or software distribution management. Data is pulled in across the network to be manipulated locally, and then saved back on a file server. Everybody (end-users) knows how this works because it’s been this way for awhile. To keep the experience value high with any new solution, we need to be able to keep this same basic application interface concept.
Enter VDI…
Basically speaking, VDI takes the user’s desktop and moves it into the data center. When done right, resources become better utilized, applications are managed efficiently, and data never leaves the friendly confines of the datacenter. Properly utilized resources means better efficiency and reduced TCO, properly managed applications means happy IT administrators, and a properly configured virtual desktop environment means users can continue to use applications the way they know.
So, with these benefits and end results in mind, our modified VDI definition will read like this:

“Virtual Desktop Infrastructure (VDI) is a new way of managing the end-user experience. With a mind toward maintaining (or increasing) the usability of the environment, centralized computing resources become better utilized, and data is more securely protected inside the datacenter. Applications are easily managed because they also exist only in the datacenter, and not spread across a corporate campus. TCO goes down, IT and end-user satisfaction goes up.”

Keep in mind we’re still in the basics here, and just defining this blog topic. There is a lot more to VDI than these three basic benefits. I might even expand on that definition some more, as we get deeper into some other VDI topics. VDI in general is a young technology, with some major vendors getting into this space in the past two years. This definition, and how we use it, will very likely change as the solution matures. We haven’t talked at all about any specific products (and there are a few). We haven’t discussed any particular pros and cons (like thin-client and offline access, which will come with the specific products). We haven’t even thought about system requirements (like solid datacenter infrastructure to support these virtual desktops, which will also come with the specific products).

We have a lot to cover, so stay tuned as the world of VDI becomes clearer to all of us.

-Bruce Heavner, GlassHouse Senior Consultant