Desktop virtualisation, with its promises of improved security, manageability and flexibility, may be on the verge of huge adoption, some experts are predicting.
But as with many new technologies, there is a catch. ROI is one of the main selling points, but desktop virtualisation requires significant upfront costs and it can easily take three or four years to realise financial rewards.
"I see huge interest right now, for many reasons," says Forrester analyst Natalie Lambert. "But the challenge is that desktop virtualisation is a very costly endeavour. I don't care what people tell you otherwise, they're wrong."
Gartner's latest numbers released this month predict that hosted virtual desktop revenue will quadruple this year, going from US$74.1 million worldwide in 2008 to nearly $300 million in 2009.
Meanwhile, a survey of 340 IT managers found that 41 percent are already investing in desktop virtualisation, and that the technology is a "critical priority" for 22 percent, according to IDG Research Services Group.
Respondents were virtualising 6 percent of desktops at the time of the survey, and expected to virtualise one-third by 2010. But the survey was conducted in April 2008, so recent economic changes could affect those numbers.
"Is [desktop virtualisation] going to break out in 2009? I don't see any reason it would," IDC analyst Michael Rose says. "Frankly, the current economic environment is going to be a significant barrier for adoption of virtual desktops in the data center."
True ubiquity could take another five years, given current financial problems and the nature of PC refresh cycles, he says.
Nonetheless some early adopters are reporting success, with users embracing the notion of being able to access desktops from multiple locations and multiple devices.
"[Virtualising desktops] is going to save us $250,000 per year that we were spending on desktop refreshes. There were some upfront costs, but we figure there will be a two-year ROI," says Dustin Fennell, CIO of Scottsdale Community College in Arizona.
Additionally, vendors such as VMware and Citrix are working on new ways of providing virtual desktops, which they believe will spur greater adoption.
How it works
In virtualised desktop environments, the operating system, applications and associated data are abstracted from the user's PC. Broadly speaking, there are two types of desktop virtualisation. Local desktop virtualisation runs the entire desktop environment in a protected "bubble" on the user's PC. Hosted desktop virtualisation stores the users' desktops in the data centre, requiring users to access their desktop images through a network connection.
Within these categories are several sub-types.
In the hosted desktop virtualisation realm, enterprises can store virtual desktops on a standard server accessed by multiple users simultaneously, or a PC blade architecture in which each blade typically serves just one user at a time. Users can connect to their desktops using thin clients, laptops or regular desktops, but hosted desktops usually preclude any sort of offline access.
Local desktop virtualisation is achieved either with a bare-metal, or Type 1, hypervisor, or a Type 2 hypervisor that is installed on top of the PC's operating system. Bare-metal hypervisors are not yet widely available, but vendors say they will provide better security than Type 2 hypervisors, because the bare-metal type runs independently of the client operating system. They also deliver better performance than hosted desktops, because applications run on the local client instead of a remote server. Bare-metal hypervisors are being developed by VMware and Citrix as well as start-ups Neocleus and Virtual Computer. Citrix and VMware plan to release their bare-metal hypervisors in the second half of this year, while Virtual Computer is in beta and Neocleus has released a limited version of its hypervisor.
Local virtualisation makes sense for mobile workers, who can be given separate operating systems, one for business use and one for personal use, says Sumit Dhawan, vice president in the desktop delivery group at Citrix. But local virtualisation has so far relied on Type 2 hypervisors, and hasn't taken off partly because there is no true independence between virtual machines, he says. When the hypervisor is installed on top of the operating system, all data that goes to the guest operating system must first travel through the primary operating system, and this overhead impacts performance, he says.
Citrix is collaborating with Intel on its bare-metal hypervisor, which Dhawan says will provide great performance for users as well as the convenience of central management for IT administrators. Unlike Citrix XenDesktop, which is hosted in the data center and affords no offline access, the planned bare-metal hypervisor will let users work offline and synchronise changes from a standardized corporate image when they log on.
Similarly, VMware is creating a bare-metal hypervisor that runs on each user's machine yet gives IT a "golden image" that can be managed centrally. VMware's long-term goal is to merge the two concepts of hosted and local desktop virtualisation, dynamically moving the desktop image back and forth between the device and data center, says Jerry Chen, VMware's senior director of enterprise desktop virtualisation.
Neocleus, meanwhile, will release its full product in beta next month and is promising far better security than exists in most desktop environments today. In addition to separating personal and business computing into separate operating systems, each operating system will run in its own "bubble," which, if infected, could simply be deleted, preserving the integrity of the machine as a whole, the company says. Centralised management tools will let IT pros set policies preventing users from accessing particular devices or applications, and governing interactions between virtual machines.
Running the numbers
To figure out the ROI for a desktop virtualisation project, an IT shop has to take multiple factors into consideration. virtualisation might be used to extend the life of older desktops, resulting in up-front savings. On the other hand, a virtualisation project might include purchasing of thin clients or other new devices. Additionally, a hosted desktop model requires servers or PC blades to host desktops and networked storage to support virtual machines.
Anecdotally, Forrester analysts have found that enterprises spend about $860 per user, plus network upgrades, to get a desktop virtualisation project up and running in the first year.
Despite healthy revenue projections, the hosted virtual desktop market will experience "growing pains" throughout this year and early 2010, according to a Gartner research note. Costs savings amount to about 3 percent to 10 percent compared with a well-managed, secure desk-based PC, the analyst firm says.
"Most customers, particularly those hard-pressed because of economic conditions, will find it difficult justifying the additional capital needed for the infrastructure build-out," Gartner writes. "New and sizable investments in the areas of storage, networks, servers, power, cooling and other infrastructure will press organizations into early investments."
Hosted virtual desktops will become less costly over time as vendors develop better management technologies, Gartner says.
At Scottsdale Community College, Fennell installed XenDesktop and other Citrix technologies both to virtualize college-owned desktops and provide remote access to students and teachers with their own devices. Previously, some students had to travel to campus even when they didn't have class, just so they could use certain applications. "Our students are just beside themselves. They absolutely love it," Fennell says.
In addition, patching desktops is easier and the college is extending the life of some older desktops by treating them as thin clients. The college can support 500 concurrent users on 12 physical servers, but is looking to scale that number up significantly.
"We needed something that would poise us to spend our money more wisely than just replacing black boxes," Fennell says. "We wanted a strategy that would not only update our technology but at the same time increase users' access."
While Fennell expects to break even in two years, it might take longer for a private enterprise undergoing a similar project because Scottsdale Community College receives an educational discount.
HP officials, who are selling blade PCs bundled with Citrix virtualisation software, acknowledge that virtualisation typically involves more upfront cost than a PC refresh, but say many customers start reaping financial benefits after little more than a year.
"The industry thought this would take off faster than it has, and I think any of the players involved would tell you that," says Dan Nordhues, director of marketing for blade clients at HP. "We're seeing indicators that this is moving from the early adopter phase to more mainstream."
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