Initial Application Streaming Alternatives to Desktops
Until recently, limitations on both the computation power of server hardware and the sophistication of desktop OS virtualization tools had limited use of fully virtual desktops, forcing companies to look at virtualizing specific critical applications instead. These architectures often required specially patched and divided client operating systems and applications typically streamed as required down to fairly simple thin clients devices. However this architecture was not something anticipated when the OS and applications were originally written and it introduced a great deal of complexity and fragility that was usually left for customers to resolve. This complexity also meant that it was only feasible for dedicated task workers who used only one or two applications.
Virtualization to Share Centralized Hardware
Virtualization has recently been applied to this problem after being widely and successfully used for servers. In part this approach was desirable because it held the potential for supporting a full native Windows OS and untampered applications, reducing the burden on IT staff and providing users with a full-featured computing environment. Consolidation of desktops onto centralized servers also promised, even more so than with server consolidation, to produce much higher utilization rates, and therefore better return on hardware investments, as typically desktop processing power had very low utilization rates for most of the day.
When is Thin Fatter than Fat?
Unfortunately the ready availability of prior generation thin clients led some vendors to try repurposing thin clients originally designed for application streaming for desktop virtualization. That, along with the use of terminal services protocols like RDP, meant that considerable hardware was needed on the client to run the client OS, network software stacks and protocol extensions needed to overcome the problems introduced by this repurposing. And along with the added hardware and software came management overhead, configuration headaches, license fees, security holes, etc. IT staff were left trying to make sense of convoluted architectures and management tool mismashes needed to make traditional thin client systems virtualize a limited form of Windows onto what were essentially miniature PCs on every user's desk. In many cases the cure was worse than the disease - making traditional "fat" PCs look very "thin" by comparison.
Incomplete Solutions are no Solution at All
Many of these vendors also provided only one piece of what was needed to deploy real-world desktop virtualization – thin-client hardware or an embedded OS or management tools – leaving customer IT staff with the arduous task of learning, building and maintaining a complex multi-vendor hardware and software integration just to deploy even their initial trials of virtual desktops.
Unfortunately these efforts to turn a sow's ear into a silk purse may have lined those silk purses for many vendors but have done little to convince IT organizations that virtual desktops are both economically and technically viable despite the apparent obvious benefits from centralizing the management of Windows desktops. What was needed was a clean-slate approach to virtual desktop infrastructure....something with components that were purpose-built and optimized solely for desktop virtualization.
