Hosting virtual desktops: Tips for a successful outcome

How do you calculate and quantify those advantages, choose the right technology and build out a successful hosted virtual desktop infrastructure (VDI)?

Calculate the implications for IT infrastructure

IT organizations that have already been down the virtualization road with servers have a leg up. They should be able to leverage at least some of their existing license agreements, as well as management tools, network equipment, networked storage and other infrastructure.

Virtual desktop architectures, which transmit graphics as well as keystroke data and mouse clicks, can tax your network, says Slattery. "If you have a lot of branch offices or home users who don't quite have the network performance you need, that may guide your decision." On the other hand, if you already have a virtual server environment and the network to support it, you may not need to invest as heavily in new switches and other networking equipment.

"Storage is also a concern because you're moving off relatively cheap disk on the desktop to a back-end SAN," says Align's Mayers. "Your cost per gigabyte is increased."

Management tools are a still a work in progress, says Gartner's Wolf. "I ask clients, if they have to add another five tools to manage their virtual desktop environment, which ones are they able to take away that they used previously? Typically, the answer is none." The most popular tools may be able to plug into enterprise management frameworks from Microsoft, IBM and others. But the integration work is unfinished, Wolf says.

Antivirus software is another hidden cost, says Wolf. Installing traditional desktop antivirus software into each virtual machine taxes CPU cycles and disk I/O. While McAfee and Trend Micro now offer special-purpose virtual antivirus appliances, most IT organizations are waiting for the second-generation product before committing to it, Wolf says.

"The net result will be that you will be running fewer desktops on physical servers than you planned for, and you can imagine how that snowballs," Wolf explains. "That means more servers, more storage ports, and the cost of supporting virtual desktops can go up as a result."

In other words, if you're running fewer virtual desktops on physical servers than you had planned because of the antivirus software and other gear needed to support those desktops, that means you'll need more physical servers. But there's no rule of thumb for this in terms of X number of servers to support Y number of virtual desktops, because there are too many variables, such as the number of applications installed in the image.

Slattery is less concerned about management tools, storage and other infrastructure, which IT already knows how to deploy and manage efficiently. "The biggest challenges come down to licensing," he says.

Check your licenses

IT needs to factor in licensing costs for virtualization software and infrastructure management tools, but the wild card is what it will cost to migrate all of those Windows licenses off physical hardware and onto virtual desktops.

Whirlpool VDI strategy focuses on customer service

For appliance manufacturer Whirlpool, which is in the early stages of a VMware virtual desktop rollout to 18,000 employees, virtual desktop infrastructure is all about improved customer service -- specifically, improved reliability and flexibility. An aging population of 30,000 desktops with an array of disparate hardware and software configurations has been generating 30% of all trouble tickets.

"A lot of that goes away when you're talking about using virtual desktops," says CIO Kevin Summers. Further, employees will be more productive because their virtual desktop environments are more stable when hosted in the data center rather than on aging PCs. Because virtual machines can stay running or enter a suspend mode after the user logs out, the virtual desktop "boot-up" process is much faster. And having all of those virtual desktops reside in the data center should make patching and updates much easier, he says.

Infrastructure problems had to be worked out during the pilot. "We had problems with the [virtualization] software, and with applications. The key challenge we have had in the application space is virtualizing Internet Explorer," Summers explains. "We had to develop a strategy together with VMware to handle plug-ins for IE. That has added to the timeline."

Virtualization allows for greater flexibility in that users can access their virtual desktops from any desktop -- or even an iPad. "People want that flexibility, to be able to use their own personal devices sometimes," Summers says. When the rollout is complete, Summers expects 60% of all desktop users to have a virtual desktop thin client or a combination of thin client and a device that they bring to work.

Several hundred virtual desktops have been rolled out. "Within 12 to 18 months, we'll have 10,000 people on virtual desktops," Summers says about the rollout. The plan is to virtualize first using existing laptops and desktops as clients, and then gradually replace those with thin clients during the normal refresh cycle. "We're going to try to phase out a lot of the old hardware," Summers says.

-- Robert L. Mitchell

The total cost depends on your existing licensing agreement. Users already paying for Microsoft's Software Assurance for Windows get the rights to create up to four Virtual Desktop Access (VDA) images for a given user's Windows-based desktop, laptop or tablet computer.

"Any device covered by Software Assurance gets the grant rights. Others, such as thin clients, require the purchase of a separate VDA license," says Gavriella Schuster, general manager of Windows product development.

For users without Software Assurance or who want to use a thin client, an iPad or a device other than a Windows-based desktop, laptop or tablet, it's a different matter. "Microsoft does not permit the Windows desktop operating system to be licensed away from the physical machine," says Margevicius at Gartner. "It requires you to purchase a separate VDA license [per virtual desktop], and that's $100 per year" per virtual desktop. (Microsoft's RDS client licenses, required for XenApp, cost a bit less -- in the range of $75 to $85 for a perpetual license. This is because the user is sharing a single instance of Windows Server rather than running a full instance of the Windows desktop operating system, Microsoft's Schuster says.)

"Because it's delivered on a virtual machine, Microsoft charges more," Margevicius says. "This is a very sore point with Microsoft customers."

In response, Schuster points out that "the VDA license includes many more rights than a standard Windows license." And while Software Assurance requires that the user has purchased an OEM Windows license with the physical client device, VDA does not. Further, Schuster explains, the VDA license provides customers "with special use rights, and it gives them access to training and deployment services as well as the rights to the next Windows release."

This was a sticking point for Touchstone Behavioral Health, which does not have Software Assurance. Porter says he already pays for each Windows license twice: once for the instance that ships with every laptop, and once for his enterprise agreement or VDA license. He estimates total client licensing costs -- Windows and virtualization client software -- at about $300 per year per seat. He'd like to see concurrent licensing. "The vendors strong-arm me into buying more seats. They're nickel-and-diming me to death," he says.

But if you're doing only application virtualization, Microsoft's product in this category, App-V, can be fairly inexpensive because Microsoft makes it available through its Software Assurance license agreements. The typical annual cost in that scenario is generally in the range of $5 to $10 per seat, Margevicius says.

Licensing issues can also derail a client virtualization project if you outsource support of your desktops to a managed service provider, Accenture's Slattery warns. "Your vendor might not have envisioned this sort of solution, and that may delay you or cause you to reopen an agreement," he says.

Finally, a Windows 7 migration can change the math when it comes to incremental licensing costs, since you may have to buy new licenses anyway. "We have customers at Align who don't have Software Assurance who say, 'If I have to buy an operating system anyway to upgrade to Windows 7 and new desktops to support it, maybe that justifies looking into this,' " says Mayers.

And if you're also upgrading Microsoft Office, virtualization may make that upgrade process easier if you don't already have an efficient, automated software distribution mechanism.

Before embarking on a client virtualization project, IT can increase the chances for success by shrinking the application portfolio, says INX's Kaplan. "Do you really need five different versions of a spreadsheet program out there?" he asks. "Probably not."

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Robert L. Mitchell

Computerworld (US)
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