Citrix Plunges Deeper Into Desktop Virtualization

Citrix Systems has unveiled plans to launch a desktop virtualization server, XenDesktop, that it will co-market with Microsoft at its Synergy 2008 user group May 20 in Houston.

Citrix will compete with VMware and other offerings on the basis of its ICA protocol-based performance and end-to-end delivery system.

XenDesktop will store a few basic images of user desktops that will be used to provision hundreds or thousands of end users. Each time a user logs on, a personal desktop will be built from a few tested components, according to that user's personal settings. Meanwhile, the amount of storage used or number of desktop images that need to be maintained will be sharply limited by IT supervision.

The approach, said Sumit Dhawan, head of the desktop product marketing group, "is like maintaining one desktop image on a data center server" as opposed to maintaining thousands of virtualized desktops or worse, thousands of physical PCs throughout the enterprise. Likewise, operating system changes or updates to applications are done once in the data center, then those parts get "dynamically assembled into a desktop" for each user with the next log-in.

As might be expected with this close Microsoft ally, Citrix has equipped XenDesktop with its ICA protocol to handle user requests and translate them into dynamic assembly of desktops. The ICA protocol is proprietary to Citrix, but Windows Server 2008 can recognize and respond to it. Other vendors of desktop virtualization will have to rely on Microsoft's slower Terminal Services Protocol, Dhawan said.

"No one else will be able to use ICA or offer dynamic assembly," said Dhawan.

If Microsoft has been behind the curve in server virtualization, it has found an ally in Citrix with which to regain ground when it comes to desktop virtualization. Virtualized desktops can run under Microsoft's V-Hype hypervisor on data center Windows Server 2008 and of course end users can be served either XP or Vista and Office applications. Citrix was previously the leader in high end application virtualization with its Presentation Server product, now renamed, XenApp. That division of labor appears likely to continue. Citrix will meet the desktop virtualization needs of large enterprises with thousands of end users and Microsoft will maintain a large base of small and medium-sized businesses through an upgraded Terminal Services.

With XenDesktop, Citrix is seeking to capitalize on a key advantage in desktop virtualization. By being able to build a new desktop with each user log-in, IT managers are minimizing the amount of storage needed to store and maintain desktop virtual machines. A fully featured Vista desktop may run up to 20 Gbytes of storage, if each is stored separately, while XenApp requires only a few megabytes of data on each user as a guide to building that user's desktop, Dhawan.

With a thousand users, "20 gigabytes per user amounts to 20 terabytes of expensive, data center network storage. That's expensive and [that form of virtualization] hasn't solved the problem," he added.

Instead of arrays of disks and their related electricity costs, IT managers using XenDesktop will rely on the rapid digital iteration of desktops in the data center, with personalization features added as they're built. XenDesktop knows key information about each user through its integration with Microsoft Active Directory or other identity management systems.

Dhawan said it's possible under some approaches to provision a virtual machine at the user's desktop and store the complete desktop image in the data center when the user closes down for the day. But those desktop images may end up highly individualized, with different users using different versions of applications and operating systems, making maintenance more time consuming and complex.

But for Citrix' centralized approach to work, the desktop virtualization process needs a high speed protocol, and it expects to retain its ICA advantage for some time.

An annual subscription for XenDesktop is priced at $45 per user for an entry level, Standard edition; $95 for a scalable Enterprise edition and $140 per user for an end-to-end desktop management Platinum edition. Perpetual licensing is also available.