For many enterprises, desktop support is a major drain on IT department time and resources. Workstations may be installed with a mixture of operating systems, especially different versions of Windows depending on the date of purchase. Maintaining a uniform operating system across all machines can be both time-consuming and incur potentially expensive upgrade licenses. And then there are the applications installed on each machine.
Desktop virtualization holds out the promise of unifying workstations and reducing the workload for IT to maintain end-user machines. Essentially, the Holy Grail of desktop virtualization is one centrally managed desktop image rolled out to every workstation, with any future updates equally and automatically deployed down the line. But implementing an architecture this elegant, can be a complex endeavor, whose own costs can outweigh those that you're trying to reduce.
Virtualization products generally come in two flavors: local applications and server-based desktops. Local virtualization apps include products like VMware® Workstation, Microsoft® VirtualPC and Sun VirtualBox. These applications run on the end-user's local machine. When supplied with a "virtual machine image" the application launches a desktop-within-a-desktop. The virtual machine image can contain a snapshot of any major operating system, outfitted in any way the IT department wants. For example, IT could create a virtual machine image of Windows® XP with Office 2003 and a custom enterprise app installed. The end user launches this virtual image on his own native desktop, be it a Windows, Mac or Linux machine. Both desktops run simultaneously, with the virtualized desktop running "on top" of the primary OS.
Local virtualization lets you separate the physical machine's OS from the OS your user may be required to interact with. But there are complications. If the virtual machine image you are deploying is a commercial OS like Windows, you'll need a volume license to stay legal. Plus, IT may still need to support the workstation's primary OS, if it develops problems that prevent the employee from running the virtualization app. One possible exception to this would be a BYOC (bring your own computer) scenario, wherein the employee is using self-owned hardware. In this case, the employee is responsible for his own equipment, but by running a virtual machine image, would be working in an environment centrally created and maintained by IT.
Server-based desktop virtualization is a more holistic solution for medium to large enterprises, but it can come with significant cost. The premise is simple enough: A data center hosts the operating system and applications that end users will access. Their own workstations are simply visual terminals that receive video data from the server. Because everything essentially lives "in the cloud," IT has complete control over the environment available to end users. Plus, any patches or updates that IT applies to the server are instantly reflected for all end users. Workstation maintenance becomes a thing of the past.
But data centers don't come cheap, and it can take a considerable server farm to seamlessly host applications for thousands or tens of thousands of end users. Because workstations are basically dumb terminals with basic networking and video capabilities; all of the processing required by every application at any given moment falls on the server to handle. Plus, the workstations needed to display the virtualized desktops come with their own cost. According to one study, when you consider the total cost of implementing a large virtual desktop deployment, the cost-per-workstation can add up to an average of 1.5 times more than supporting a traditional desktop PC.
Seeing real savings from a virtualized desktop deployment requires both scale and time. Data center processing power becomes cheaper as the scale increases, because the investment in the initial infrastructure is the primary expense. Significant upgrades in processor power and storage capacity can then be added for marginal additional expenditures. Desktop virtualization can provide a functional and financial benefit over traditional desktop PCs in an organization willing and able to invest in a large-scale deployment that will be in use for a long period of time. But for a small deployment, the upfront costs in resources and training may exceed the cost of simply supporting traditional desktop PCs.
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