When It Comes To VDI, Forget The Device 2

Desktop virtualization sounds like a simple follow-on to server virtualization. You put a hypervisor on the desktop, the way you did on the data center server, and run virtualized applications under it, right?

Well, no. As anyone who has taken this on knows, virtualizing the desktop is an entirely different breed of cat. Understanding it starts with the user--not focusing on the device that you're virtualizing. You need a desktop virtualization strategy that can follow employees around, regardless of where they are or the machines they're using. That, admittedly, isn't easy to implement.

IT teams that focus on devices and not people will eventually find themselves, after considerable expense, enmeshed in a series of moving parts that don't work well together. The predicted savings that came so readily on servers won't materialize.

Say, for example, that you initiate desktop virtualization with a standard desktop environment in mind. Once the first high-ranking power user complains, you're forced to customize his or her desktop, and the customization disease spreads faster than dengue fever. Your grand plan to serve all employees with a few master desktops is gone, and now you're storing a thousand custom desktops every night. The storage requirements alone eat up anticipated savings.

Or, you play hardball and define only a few roles, into which everyone must fit, each with a single master desktop. That keeps storage costs down--yet earns IT a reputation for being inflexible and out of touch.

A (seemingly) more savvy IT manager elicits role definitions from employees and lets them classify themselves, leading to more contented users. That is, until people need to travel, and IT gets bombarded with questions with no good answers. Yes, they can use the old Office software on the laptop. But if they're looking for Excel spreadsheets they started while connecting to the network, that data's in the data center, not their machines.

Success in virtualizing desktops in the office turns into a liability as people go mobile. You'll need to provide mobile PC access, using a hypervisor on the machine for offline access that syncs to existing data the next time the machine hits the corporate network.

Done? Maybe, until employees stream back into the office after the holidays with new iPhones and Droids, and there's another strain of dengue fever running wild. If they use so many consumer apps on their phones, why can't they get to their virtual desktops from those same devices? Oh, and about this iPad ...

The device options are only going to multiply. Thus, as part of your desktop virtualization strategy, you'll want to empower end users to do as much of the provisioning and maintenance themselves as possible. Your plan must enable the disconnected user.

The Smartphone Factor

Charles Kanavel, director of technology for Campbell Union High Schools, supplies 2,800 desktops to 8,000 students in seven high schools in the San Jose area. Each PC in its aging inventory serves at least five students a day.

One-fifth of Kanavel's budget, or $550,000, is earmarked for hardware replacement. A year ago, he applied that amount to implementing desktop virtualization on existing PCs, spending $300,000 of the hardware budget on virtualization and saving the cash-strapped school district $250,000. The district then let students log into the virtual desktops from their home PCs and Macs.

Then came smartphones. A survey found that while 70% of students had broadband at home, an astounding 95% carried browser-equipped, multimedia-capable phones. In January, Wi-Fi traffic jumped 30% as students returned to school with iPhones they got as gifts. Students tend to focus on applications rather than platforms (Windows or Mac). "Applications are what kids ask for," Kanavel says. Students can "type 60 words a minute on the iPhone, write papers on them, and store them on the district's central servers," he says. "They're constantly uploading content."

Virtual desktops are the answer. Kanavel serves a mix of 600 different applications in use by the district via 18 distinct types of users. He extends the virtual desktop to Windows PCs and Macs. For smartphones, the Citrix Receiver client software currently is limited to the iPhone; Kanavel has been told Blackberry support is coming this summer.

The investment breaks down like this: $100,000 on server-attached storage, $100,000 on blade servers, and $100,000 on software to virtualize apps on central servers, to create virtual desktops that are streamed to end user machines, and to run the virtual applications. Citrix's XenCenter is used to manage the life cycle of virtual desktops.

Kanavel serves 200 desktops from each $6,000 blade server. He has virtualized 500 desktops since August and that will jump to 1,100 by mid-summer. The goal is to eventually replace all PCs in the district with thin clients and manage them from centralized servers. When done, he expects the district to save 40% per desktop in operating costs. Capital savings will be less impressive, since thin clients will need to be replaced about as often as PCs, at $400 to $600 a unit.

While Kanavel picked Citrix, VMware offers a similar lineup of desktop virtualization options, and Microsoft's Hyper-V with Virtual Machine Manager management tools also is in the mix.

The biggest difference businesses face is security. Citrix recently added a plug-in to its Receiver client software that, if an employee's working offline, stores data in an encrypted "safe zone" separate from personal data. That data's transferred to the data center once the machine's back on a network. Citrix is working on a "wipe" feature that would recognize when a laptop reported stolen connects to a network, and delete any remnant of the virtual desktop and its data from the machine.

The technology isn't perfect for creating a device-agnostic virtual desktop strategy. VMware and Citrix have multimedia protocols that query what device is connecting and try to gear speed of presentation to that device. But the software recognizes a limited number of devices and doesn't always adjust displays or format to the device.

Why bother with virtual desktops? IT efficiency is one reason. Kanavel supports 200 users per server, and new multicore servers employing six- and eight-core CPUs should be able to support more than 250 users. Cisco Systems says its new blades, designed for virtualization, will support 330 per blade.

Another reason is simplified desktop management. Software changes are implemented on central servers and streamed to machines the next time users log in. That simplifies migrations to new applications and operating system versions. The desktop becomes less rigid and less OS- and device-specific. It becomes a software entity capable of adapting to a user's shifting location, need, and available computing instrument.

Companies have been slow to adopt desktop virtualization because the ROI can be hard to pin down. It's not for everyone, but companies must look beyond the IT efficiencies and today's devices.

As emerging, flexible forms of desktop virtualization adapt more easily to various devices, it will ease what seems a perpetual tension between users and IT managers in this age of consumer tech. Increasingly, the device will reflect user choice, while at the same time operating under the control of IT policy.

It's not a cure-all, and new problems will emerge. But desktop virtualization is a technology whose time has come. The question is whether IT managers can implement it in a way that makes users eager to come along.