Developing all the necessary drivers needed by PC users has proven to be one major challenge. Another roadblock may be persuading PC vendors to ship and support these hypervisors with their hardware, according to research firm Gartner.
Citrix and VMware were expected to ship their respective products, XenClient and Client Virtualization Platform, before the end of 2009. Now VMware hopes to have something out by the end of 2010. Citrix is waiting for the results of an ongoing closed beta test before committing to any dates, according to Dave Austin, Citrix's director of product marketing in Europe, the Middle East and Africa.
A bare-metal hypervisor, also known as a type 1 hypervisor, runs directly on system hardware rather than on top of a host operating system. That allows one or more operating systems to run on top of the hypervisor as virtual machines.
Desktop virtualization allows corporate IT departments to easily ensure a standard operating environment for all users, but the current approach requires that the desktop environment be networked to a server where the virtual OS is actually running. With bare-metal desktop hypervisors, performance is improved because the system is running locally, not over a network, and users are also able to work offline.
They would also allow companies to create a standardized operating system image that can be rolled out on all desktops, and then updated and managed centrally. For it to work, the PCs need to be compatible with Intel's vPro technology.
Currently, there are a couple of issues delaying the two companies, according to Mark Margevicius, research director for client computing at Gartner.
From a technical perspective, the development of bare-metal hypervisors for client-side virtualization is made more complex by the plethora of components the hypervisor must interact with on the PC. So drivers have proved to be a big challenge for VMware and Citrix, Margevicius said.
And the vendors agree: you have to take into account networking, Bluetooth, graphics hardware, and other common client-side components, according to Austin. In the server world, where bare-metal hypervisors have been around for ten years, the hardware compatibility list is much shorter and well-defined, according to Fredrik Sjöstedt, VMware's director of product marketing in Europe, the Middle East and Africa.
There aren't just technical challenges that have to be sorted out. PC vendors will have to support the products, and bare-metal hypervisors aren't necessarily beneficial, according to Margevicius. That's because they may make it easier and cheaper for companies to switch vendors when they can build a standardized desktop image that is independent of the hardware. They can change the vendor, but the image stays the same, Margevicius said.
"If the costs come down, customers will be doing bids on PC hardware on a weekly basis," said Margevicius.