With somewhere around 550 million corporate desktops today, 5 to 10 million are estimated to be delivered as some form of virtual desktop -- also referred to as "centralized desktop" -- and that number is expected to roughly double by 2009. Centralized desktops encompass three major approaches: terminal services, or server-based computing; virtual clients; and PC or workstation blades. (Application virtualization and streaming is an extension to these, which I'll discuss in a future column.) These three approaches share the advantage of centralizing management of the desktops and securing desktop data in a central location. One or more of these approaches might be worth considering as part of your customers' future desktop strategy.
Terminal services/server-based computing
Terminal services and its extensions have been in production longer than either of the other approaches, offering an early hybrid of client/server computing and mainframe time sharing. This approach, known as server-based computing (SBC), allows multi-user applications to run on a central server (running terminal services or Citrix Presentation Server), which users typically connect to from a thin client. Today, according to Citrix, there are more than 800,000 servers running a Citrix infrastructure, at more than 200,000 companies -- representing the largest portion of the centralized desktop market. Users connect from thin and fat clients of many types. This approach is most familiar for applications where a user runs the same multi-user application and nothing else (for example, at call centers). SBC offers the highest ratio of users per server -- Citrix servers today can support 250 to 500 users per server.
In addition, as Citrix leverages its newly acquired Xen virtualization technology, it will be in a great position to offer leadership across the centralized desktop space, via a stronger integration of SBC and virtual clients, with central management of users connecting to whichever is best-suited for a particular need. Citrix channel partners who also understand virtualization and where Citrix, Xen and VMware fit (today and in the future) have an opportunity to lead in the newly burgeoning space of centralized desktops.
In organizations that have successfully deployed server virtualization technology (which to date has generally been done using either VMware or one of the Xen-based offerings), more and more users are dabbling with expanding that virtualization out to the desktop. VMware calls its desktop virtualization approach Virtual Desktop Infrastructure, or VDI; Citrix dubbed it Dynamic Data Initiative (DDI); IBM and others use the term "virtual clients."
This approach creates a virtual machine for each desktop; a user can connect to the virtual machine via a piece of software called a connection broker, using a thin client or browser. Connection brokers offer a wide range of functionality and are available from a variety of vendors, including VMware (with software from its Propero acquisition and now offered as Virtual Desktop Manager, or VDM), Citrix (whose broker was originally called Desktop Broker, then Desktop Server and now XenDesktop), Leostream, Provision Networks, ClearCube and others. Functionality ranges from minimal capability (connecting a user to a specific virtual machine to broader virtual client functionality (for example, connecting to a pool of VMs and adding other management capabilities), to incorporating broader connection options (which can include virtual clients, PC blades and terminal services/SBC).
The move from virtualizing servers with VMware to deploying VDI has been a slow process, as desktop changes tend to be, but as time goes on, it will represent a significant opportunity for the channel. Citrix's acquisition of XenSource, and where it goes from here, will have a big impact on this sector of the market, so it's important for channel pros to keep an eye on this space.
For channel partners selling both VMware and Citrix products, the Xen acquisition by Citrix and the huge growth that's projected for the overall centralized desktop market represent both a challenge and an opportunity. As both VMware and Citrix advance their respective technologies, your customers will have new choices for redefining their desktop strategies and expanding centralized desktops to a broader segment of their user base.
Just as virtualization technology is moving from the server to the desktop, so is blade technology. Following the blade server model, PC blades are essentially a PC on a card (blade), which is inserted into a centralized blade chassis. Sometimes this is the same chassis as server blades, sometimes it's a different chassis, depending on the vendor and the type/power of the desktop (PC vs. workstation). The PC/workstation blades are centrally located, with the user interface for keyboard, video and mouse run remotely to the user location via a variety of options (on a local connection or over IP). The "remoting" of the user interface is sometimes called "PC over IP."
Early PC blades gained significant traction in the financial trading and healthcare industries, due to the high security requirements and benefits of being able to remove the PC from the user area and lock it in a secure location. ClearCube and Hewlett-Packard (HP) led this market, with IBM announcing a higher-end workstation blade this year for the IBM BladeCenter Chassis. A new player, Teradici, joined the game this year (its technology is now OEMed by IBM, ClearCube and Verari), with video compression technology that significantly improves the user experience when running graphics. This technology will extend the value of PC/workstation blades significantly. With a PC/workstation blade configuration, the user operates a thin client, which goes through a connection broker to a PC/workstation blade or pool of blades. Again, functionality (CPU power, graphics capability, quad monitor support, local device support) and price vary by blade vendor and connection broker, but all PC/workstation blades offer the advantage of central management and increased security. While PC/workstation blades will continue to be somewhat of a niche market, improvements in the user experience are expanding that niche. PC/workstation blades represent an excellent opportunity for expanding your reach into other parts of your customers' organizations, particularly if you sell blade servers today.
For more information
Focus Consulting is currently working on a major research series on desktop delivery alternatives, including drivers, use cases, considerations, user requirements, vendor options and user case studies. If you would like information or help in this area or if you have interesting user experiences or product/service offerings, please contact us at www.focusonsystems.com.
Barb Goldworm is president and chief analyst of Focus Consulting, a research, analyst and consulting firm focused on systems, software and storage. Barb has spent 30 years in various technical, marketing, senior management and industry analyst positions with IBM, Novell, StorageTek, Enterprise Management Associates and multiple successful startups. She recently released a book titled Blade Servers and Virtualization: Transforming Enterprise Computing While Cutting Costs and published by Wiley, and is working with her team on the upcoming Focus Research Series on Desktop Delivery Alternatives. Barb can be reached at email@example.com.
This was first published in November 2007