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Is that a desktop in your pocket?

Virtual servers have changed the way businesses are run. Now, virtualisation vendors have set their sights on your PC.
Written by David Braue, Contributor

In the not-too-distant future, the induction process at your new job could very well involve signing the usual HR and payroll forms, then being given a memory stick holding a file that contains your entire desktop computer, preconfigured with the applications you will need for your particular role.

Instead of having your own desktop computer, you will simply sit down wherever you like, then plug the memory stick into the USB slot on a generic office computer. The system will automatically load up your own wallpaper, desktop, applications and settings -- constrained, of course, by enforceable corporate standards -- and save any changes back onto the memory stick.

Storing your entire digital life on a memory stick -- or, if you have a big life, an iPod or other hard disk-based device -- is the most significant change in the way computers have been managed for decades. Yet it's a much more efficient solution: standalone computers are expensive, complex, error prone, and collectively form a black hole into which a huge proportion of IT administrators' time disappears.

A recent IDC survey found that improving management and automation tools was the top priority amongst Asia-Pacific companies, cited by fully one-third of respondents as their major concern.

While automated software distribution tools have eased the process somewhat, desktops have long been a thorn in the side of every IT manager. The only other viable desktop alternative -- thin client software using Windows' built-in remote desktop protocol (RDP) or Citrix Systems' independent computing architecture (ICA) protocol -- works in some situations but is poorly suited in others.

Enter virtualisation, which replaces burdensome hardware with a single file that contains the image of a computer's hard drive, separating the operating system and applications from the hardware they run on.

Getting virtual
The ability to run many virtual computers on a single server has made virtualisation the hottest trend in enterprise technology. Server virtualisation has proven incredibly adept at slashing overhead expenses, reducing power consumption, extending the life of legacy applications, and improving fault tolerance by allowing disk images to be moved between systems in the event of a failure.

Little wonder it was named as the top priority by 14 percent of respondents to IDC's end-user survey. Now, thanks to the efforts of virtualisation market leader VMware, Symantec subsidiary Altiris, and start-ups like RingCube Technologies, the benefits of virtualisation are being turned towards the desktop to provide users with access to corporate applications in completely new ways.

By divorcing the desktop operating system and applications from a single computer, desktop virtualisation solutions create an environment that Raghu Raghuram, vice president for product and solutions marketing with VMware, calls "Desktop 2.0".

This vision is built around "the notion of mobility and portability of a desktop," he explained. "This desktop is always available, always on, kept with all the resources it needs, and accessible from anywhere. We're using the virtual machine as the unit of lifecycle management."

Since Desktop 2.0 images are just files, it's easy to host large numbers of virtual desktop files on one or more powerful servers, allowing companies to keep all of their corporate desktop images in a single central location while providing a full set of features to users.

Because the desktops are stored in a single place, they can be easily upgraded with new versions of applications or even completely new operating systems; the next time they log on, users will simply access the updated virtual image and be up and running.

This technique has proven handy for companies upgrading to Windows Vista, said Adam Jaques, manager for advanced products strategic services with Citrix Systems, which recently released its Citrix Desktop Server (CDS) to enable server-side desktop hosting. "There's a lot of saving to be made in the way patches can be made and operating system refreshes can be done," he explained.

"One of the things we do regularly is a one-click upgrade to Vista, whereas normally you'd have a lot of downtime to do this. You can essentially, one morning, say 'I'd like to have this group of users log into a Windows Vista machine' and do that through the management console."

CDS works by running the virtual desktop files on the server, then using Windows' RDP to connect the server application to those files. CDS then converts the actions to Citrix's own ICA protocol, which is available on everything from obscure desktop operating systems to mobile phones and Web browsers.

VMware's Virtual Desktop Infrastructure (VDI) system offers similar functionality. Yet while this approach lets users access virtual hosted desktops from anywhere they might happen to be, it doesn't allow users to take their desktops with them; for that feature, it's necessary to look towards VMware ACE Enterprise Edition, which allows virtual desktop images to be extracted from the hosted environment and stored on removable media.

ACE images are written along with a bootstrap loader that lets them run on a range of operating systems. This means you can store your Windows workspace on your iPod when you go home for the day, then plug it into your Linux or Mac OS X desktop at home and still be accessing your work desktop and applications. The end result is similar to that of Parallels Desktop 3.0 for Mac, which loads Windows, Linux and Solaris machine images in virtual machines that seamlessly integrate with Mac OS X desktops.

Desktop 2.0
Using virtual desktops instead of real ones may seem like a lack of control to some users, but it will be a boon to others -- particularly those that often travel and want to take their work from one place to another.

In the longer term, the ability to run full-featured desktops on a central server farm will give rise to new companies offering access to desktops managed from purpose-built datacentres. Such desktops will likely be leased to companies at a flat monthly rate, saving them the considerable cost of paying IT staff to keep a fleet of conventional PCs running.

Yet while virtual desktops give companies a range of new capabilities, they also present a different kind of risk model than that of conventional PCs. For example, companies worried about data security need to consider the impact of employees taking their entire desktop environment -- and sensitive corporate documents -- home on a memory stick or iPod. While a lost desktop could easily be replaced, proprietary data would be available to anybody finding the memory stick.

For this reason, virtualisation vendors are building a range of management features into their desktop server applications. For example, ACE images can be configured with limits on the time that a desktop image can be used. This feature is invaluable for companies with contractors, since the virtual image can be offered on a memory stick at the contract's commencement but will become unusable once the set contract period has expired.

"Corporations want to be able to manage those endpoints," said Paul Harapin, managing director of VMware Australia-New Zealand. "Every customer is going to have a different view of what they see as the standard operating environment [SOE] for a particular group of users. This approach lets companies deploy a SOE with a whole range of policies and security."

Virtual desktops offer other benefits: for example, any virus outbreaks or security issues inside a virtual machine cannot escape to affect the host system. Their ephemeral nature also has a downside, however: companies wanting to deploy virtual desktops in large numbers may also need to figure out a way to backup the data on specific images -- or how to force users to save data on centralised servers that are automatically backed up.

Such issues will be well addressed as virtual desktop applications reach maturity in the next few years. For now, however, the evolving technology offers tantalising possibilities for companies that have tired of trying to keep up with fleets of PCs gone wild. And whether you let your company's datacentre host your desktop for you or carry it with you on your keychain, the fundamental truth remains: virtualisation is here -- and your desktop may never be the same again.

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