These days, everyone is excited about the promise of PC virtualisation, but with so many different flavours out there, it's hard to know where to start. The idea of reducing a fully functional desktop into a single file that can be carried on a USB disk and run on any PC is exciting to users. But virtualisation's real benefit lies in its potential to reduce management and support burdens, improve security and reliability, and lower total cost of ownership.
We're not there yet. Figuring out how to deploy the right mix of desktop virtualisation technologies at scale, and how to manage across all of those virtual environments, will be the big nut to crack in 2008. For most oragnisations, this will be a year to test and experiment with smaller rollouts.
We've come a long way since desktop virtualisation meant using thin clients that interacted with Windows applications running on a Citrix MetaFrame back end. Today, you can virtualise individual Windows applications (think Softricity) or entire virtual PCs (VMware ACE), and you can choose between having virtual environments execute on the PC or on back-end hardware (Citrix Xen Desktop, Presentation Server). For virtual environments that execute on the PC, some products (Kidaro, Moka5) allow streaming of centrally managed virtual machine images and updates down to the client. Kidaro adds a management wrapper around the virtual PC that includes tight security controls to allow it to run securely on unmanaged Windows PCs.
But desktop virtualisation is not a one-size-fits-all proposition. Not only do you need to choose a variety of products for different needs, but in some situations, you might need to deploy virtualisation in layers. For example, you can issue a plug-and-play VMware ACE virtual PC that includes its own instance of Windows, and then use an application virtualisation product like Softricity to create individually isolated, virtualised Windows application instances running within that environment. There are good reasons why you might want to do that, but that's also a lot of complexity to manage.
Application virtualisation products are needed because they redress a core failure of Windows: the inability to control misbehaving application installs that create registry or DLL conflicts. Application virtualisation lets IT avoid much of the regression testing otherwise required to create a reliable desktop system image. It also lets older applications to run on a newer version of Windows and can allow two versions of the same application to run side-by-side.
In the future, this capability may be integrated into Windows itself, says Natalie Lambert, an analyst at Forrester Research. She predicts that Microsoft will roll its Softricity technology into the next release. It will become the ultimate workaround for the problem of misbehaving applications, and the standard-bearer for all future deployments of Windows applications. "Three years from now, every [Windows] application will be virtualised," she says.
Once you choose the right tools, there's the question of how to manage them. Today, you do that piecemeal — even within a single vendor's product line. VMware's Virtual Desktop Manager works for hosted VDI environments, for example, but you'll need a different tool for those VMware ACE environments, and another for Thinstall, the virtualisation software that VMware recently acquired. Other vendors have their own tools, of course.
But don't let that stop you. As with server virtualisation, the enterprise-class tools will evolve as users climb the adoption curve. In the meantime, the ability to abstract the corporate work environment away from the vagaries of the underlying PC hardware and host operating system — and to keep squabbling applications apart — makes for a compelling business case.
Robert L. Mitchell is a Computerworld national correspondent. Contact him at Robert_Mitchell@computerworld.com