A couple years ago, TechRepublic writer and IT consultant Steven Warren told me that if he were starting an IT department from scratch, he would seriously consider buying a giant server and simply virtualizing all of the desktop machines. I've been trying to get to Steven to flesh out this plan into a TechRepublic article for over two years (maybe calling him out publicly will provide new motivation).
This whole idea of the virtualized desktop was thrust back into the forefront of my cluttered mind this week when Microsoft announced that it was changing the licensing terms of Windows Vista to support diskless desktops. With diskless machines, the strategy is a little different than virtualized desktops, but the goal is essentially the same.
In brief, the biggest motivation for virtualized desktops for Steven was to increase the manageability of desktop machines -- one of the biggest pain points for any IT shop -- by centralizing them in the data center and taking advantage of the power of a virtualized version of Windows, which can be customized, upgraded, and even replaced much easier than a traditionally-installed version of Windows. Meanwhile, users could work in the same PC client environment that they are accustomed to. In fact, they could work in that environment from anywhere -- from their home PC, in the airport, at a client location, etc.
Without stealing Steven's thunder, here's the kind of setup he had in mind. In the data center, it would feature a big server box running virtualization server software (and 100s of virtualized versions of Windows XP, for example). At the desktop, the client machine would be a thin client (like the ones from Wyse) or a bare bones PC running Linux. The user could then access their desktop by opening their client and clicking a basic HTTP link or shortcut which connects them to their virtual machine in the server room. Then the user could click the virtual machine into full screen mode and have the same experience as sitting in front of a standard PC.
The diskless desktop scenario that Microsoft was talking about earlier this week involves a slightly different scenario. A user has the same desktop PC hardware that is widely in use today, except that the hard drive no longer lives inside the PC. Instead, the drive is located in the data center and the PC accesses it over the network.
Right now, this diskless desktop scenario probably has a better chance of being widely adopted than the virtual desktop scenario, even though it is not as robust. The biggest advantage of the virtual desktop scenario is that a user can potentially access her work machine (with the help of an Internet connection, a Web browser, and a VPN) from anywhere, even from PCs running different operating systems such as Mac OS X or Linux.
So why is the diskless desktop more likely to succeed? In the short term, it is simpler and easier to understand for enterprise IT departments, and it is more likely to be supported and pushed by the big hardware vendors (i.e. IBM, HP, and Dell) because it is not such a radical departure from the current hardware and software model.
Conversely, the virtualized desktop solution feels a little too much like the current Citrix and Wyse solutions, which have never gained critical mass as a desktop user model. Nevertheless, I do think the virtualized desktop solution is a better and more powerful solution than either Citrix or the diskless desktop, and both IBM and HP are talking about jumping on the virtualized desktop bandwagon. Those vendors could potentially help simplify and popularize this solution, and enterprise IT would be better for it if they did.
Distributed full client desktops are overkill for so many users and they create a bevy of additional storage, security, and manageability problems for IT. This is a long-standing issue that has needed to be resolved for almost two decades. The predominant desktop model simply wastes too many resources, locks the user into one physical machine, and is a manageability nightmare. Virtualized desktops offer the best long-term solution -- at least the best solution currently on the horizon -- while diskless desktops could be an interim step to help break up the conventional wisdom of putting a full client PC on every desktop and open the door for virtualized desktops.
Of course, I should also mention that the biggest caveat to a virtualized desktop environment is that it puts a lot of additional pressure on the network and on IT to make sure the network is bulletproof and redundant. If it is to become a mainstream solution, this solution will likely need to be accompanied by a local caching option in which mail and important documents can be available to the user even if a network connection is down or unavailable.
TECH: Virtualized desktops and diskless desktops could finally provide a viable alternative to the inefficient full client PC model that dominates most enterprise IT departments.
SANITY CHECK: Diskless desktops aren't a radical departure from the current desktop PC model, but they do provide some centralization and manageability improvements and could help break up the current PC model. Virtualized desktops are a much more powerful solution, but they will require more simplification and support from big vendors, better local caching options, and better network uptime and redundancy from IT.