There's an element of Groundhog Day to the world of desktop virtualization: Every January kicks off the year that virtual desktop infrastructure (VDI) will hit the mainstream ... until the next January comes around, and we hear the same thing all over again.
There's no doubt there are potential benefits to implementing VDI: easier, centralized desktop management; better security because data resides in the data center; the ability for employees to access their desktops from any device, anywhere with a network connection and a compatible viewer.
The big drawback remains cost: The cost of putting in the server, storage and network resources to enable large (or even small) numbers of desktops to be virtualized and run from the data center. It can also be complex to deploy and manage (although products like Citrix's VDI-in-a-box aim to address this) and the fact that the system is largely reliant on a network connection from the end user's access device back to the virtual desktops running in the data center can be a major inconvenience.
To address these drawbacks, Massachusetts-based Virtual Computer has turned the whole thing around with a desktop virtualization system that has the virtual desktop running on the end user's computer rather than in a data center. It's a system the company calls Intelligent Desktop Virtualization, or IDV. (IDV -- you see what they've done there?)
IDV works by placing a bare metal hypervisor (called NxTop Engine, based on Xen) on the end user's PC, and then running a virtual machine with the OS and applications on top.
What's the point of that? "Our premise is that it is easier to manage things this way," said Dan McCall, the company's president and CEO. "With virtualization technology at the endpoint, we offer the management benefits of VDI without customers having to incur the cost of the infrastructure." Hence, IDV can cost a fraction of what running a VDI environment does, he claims.
With IDV you get the benefits of central management because each desktop checks in with a desktop management server running called NxTop Center in the data center. From there, virtual machines containing entire desktop images can be assembled and pushed out. Patches and updates can also be readied and pushed out to users on a one-to many-basis; if they work on one test computer, they are bound to work on all the computers in the field since they are all running identical virtual hardware. Perhaps most importantly, user data is synchronized and stored in the data center as well as on the end-user's machine, so in theory two copies of each desktop exist: the local copy running on end-user machines, and the desktop image and synchronized data in the data center.
Since IDV relies on virtual machines running locally, users aren't reliant on a network connection to access their virtual desktop. That means they can work on a plane, for example, with data changes synced with the server the next time they connect to the network. It does mean that the data stays on the end user's machine instead of being tucked away safely in a data center, but the system encrypts all the data, so in the event a laptop gets lost or stolen, it's unlikely anyone could access it. Lost laptops can also be remotely wiped, in the way that corporate cell phones usually can, and USB ports can be locked down to prevent anyone removing data using mass storage devices.
But how does an employee carry on working if she loses her laptop? With VDI she can simply buy or borrow another, head to a hotel business center and get onto a PC, or pull out her iPad. Within seconds she can access her desktop just as she left it, so long as there's an Internet connection available.
Therein lies IDV's downfall, as this is simply not possible. In an office environment the user can be provisioned with a new machine with NxTop Engine installed, and then wait half an hour or so while his virtual machine image and data is downloaded to it. On the road, things are somewhat trickier: McCall suggests buying a new laptop, installing the NxTop Engine hypervisor, perhaps from a USB backup stick, and then waiting around for the desktop VM to download. But buying a new laptop is not always an easy matter on a rainy Sunday night in many parts of the world, and downloading the VM could take forever on a slow and unreliable foreign Internet link.
So there we have it: IDV offers reduced costs compared to VDI on one hand, but less of the convenience of accessing a desktop from almost any device on the other. Is it enough to enable desktop virtualization to finally live up to its promise? Virtual Computer claims to have around 150 enterprise customers for the system so far, but you can't help thinking that IDV isn't going to break into the mainstream this year any more than VDI will.
Maybe next year though. Sounds like Groundhog Day all over again ...
Paul Rubens is a journalist based in Marlow on Thames, England. He has been programming, tinkering and generally sitting in front of computer screens since his first encounter with a DEC PDP-11 in 1979.