In-Depth

The Rapidly Expanding Universe of VDI

One of the hottest virtualization markets to date is turning into a vendor free-for-all as a mixture of established and startup companies rush to stake their claims.

Virtual Desktop Infrastructure (VDI) continues to generate a tremendous amount of interest from IT organizations because of such potential benefits as manageability, supportability, security and availability -- and despite an initial slow rate of adoption, more and more companies are implementing this promising technology. According to the Burton Group, the VDI marketplace is going to be worth in excess of $65 billion by 2013. Of course, a potential market of that size holds a tremendous amount of interest for every vendor with a story to tell.

Perhaps because of this potential, there's some debate as to what exactly constitutes a VDI. Does it, for example, include the multiuser approach that Citrix Systems Inc. has dominated for such a long time, or is it more accurate to say that it requires a separate instance of the operating system? While arguing semantics isn't unusual as vendors seek to position themselves as market leaders, the reality is that, for many IT organizations, this discussion is irrelevant. The fact remains that there are a number of different approaches and vendors offering the ability to virtualize the end-user computing environment. In this article, we'll take a look at some of those approaches and vendors.

Market Leaders
Since the early 1990s, when Citrix introduced MetaFrame, it has been a major player in the market for virtualization of end-user computing. Along the way, Citrix also helped Microsoft gain its position through licensing and the resulting Windows Terminal Services. As one of the early pioneers and innovators in the multiuser computing space, Citrix has leveraged that customer base and expertise into a market-leading position. While the acquisition of XenSource lead to a plethora of products -- and an apparently unfocused Citrix -- the company's strategy has solidified over the last 18 months. Now that the various products and tools have become assimilated, Citrix offers choices that customers want.

With the recent release of XenDesktop 4 and significant customer acceptance of the upgrade path from XenApp -- which in one form or another has been the mainstay of Citrix for a number of years -- Citrix seems poised to remain at the top of the heap. One of the mainstays of this recent success has been its High-Definition User Experience (HDX) technology. HDX is an umbrella for a series of technologies that facilitate improved capabilities and, more importantly, a rich user experience. Technologies such as HDX Plug-n-Play, RealTime and WAN Optimization help facilitate a VDI experience that's often indistinguishable from a traditional desktop, which is crucial to user acceptance. Utilizing these and other technologies, Citrix recently disclosed in its financial results that it sold 1.5 million seats of XenDesktop during the last three months of 2009 and the first three months of 2010. A recent investment in Kaviza Inc. and its VDI-in-a-box product only underline the Citrix commitment to desktop virtualization.

Microsoft, which is rapidly expanding its market presence, has also become a major player. There are many reasons for this, including the continued dominance of Windows as well as the company's success in penetrating the server virtualization market with Hyper-V. However, Microsoft has never been a company to rest on its laurels, and it's making significant improvements to its desktop virtualization technologies such as App-V. These improvements come in terms of more favorable licensing agreements, a stronger commitment to the VDI space and improved technology.

Microsoft offerings now come in three distinct packages: VDI, Session Virtualization and Microsoft Enterprise Desktop Virtualization (MED-V). By utilizing the entire Microsoft virtualization stack -- including App-V, Remote Desktop Services, Hyper-V and System Center Configuration Manager -- the Microsoft VDI offering bundles the best that Microsoft has to offer. Microsoft also allows partners such as Citrix the ability to enhance these suites with their own products, which creates compelling solutions. For less-complex or less-intensive user needs, Session Virtualization also utilizes Windows Remote Desktop Services to offer a virtual computing environment. MED-V is designed for larger enterprises that have application compatibility issues but still wish to upgrade their desktop environment. MED-V offers a means to run legacy OSes in Windows 7.

In the pure VDI market, VMware Inc. is generally considered to be the No. 1 vendor, with 7,000 customers and 1 million seats of VMware View. Regardless of market share or definition, VMware has an excellent VDI product. With the introduction of View 4 at the end of 2009 and the inclusion of PC-over-IP (PCoIP) technology, VMware took a major step to ensure the best possible end-user experience. On the server side, the combination of View 4, vSphere 4 and the latest Intel processors introduced some significant improvements in virtual machine (VM)/CPU density. (The introduction of View 4.5 was put off at the last minute, and no new date has been set.) In fact, VMware now claims users can run up to 16 VMs per processor core. With a strong suite of management tools to complement its VDI offering, VMware offers a complete virtualization solution. Moreover, as a pure virtualization vendor, VMware continues to be one of the leading industry innovators.

Other Contenders
Of the more-established players, Red Hat Inc. and Oracle Corp. both have VDI products and a story to tell around their place in the market. Of the many less-established contenders entering the VDI marketplace, there are a number of companies and products worth considering, including those from AppSense, RingCube Technologies Inc., Unidesk Corp. and Kaviza. While many of these products have similar features and functionality, they differ in how their virtual desktops are deployed and managed. Moreover, the new entrants in the marketplace can often be distinguished from more established players because they're more clearly focused on how to solve two of the most pressing problems of deploying desktop virtualization: cost and complexity.

Red Hat
While Red Hat has a solid reputation as an OS vendor, its virtualization story has lagged behind its competitors. That changed in June, when the company announced the general availability of Red Hat Enterprise Virtualization 2.2, which includes new scalability capabilities, migration tools and features to expand performance and security. On the desktop side, Red Hat released Red Hat Virtualization for Desktops, which allows customers to deploy VDI capabilities. Those capabilities include a Web-based connection broker, with which users can access hosted virtual desktops, and the open source Simple Protocol for Independent Computing Environments (SPICE protocol) for remote rendering technology, which competes with HDX and PCoIP.

Red Hat Virtualization for Desktops offers limited support for the virtualization of desktop OSes, but it supports Windows XP and Windows 7, so it should satisfy most organizations. Management and deployment is handled through four elements, including Image Manager, Provisioning Manager, Connection Broker and HA Manager. With support for multiple virtual CPUs and advanced memory-management techniques such as page sharing and ballooning, Red Hat Virtualization for Desktops offers tremendous efficiency in the use of hardware resources with a resulting increase in the density of VMs per physical processor.

Oracle
Oracle is another company that has struggled with virtualization. Although the company has a very large portfolio of enterprise products, virtualization has always seemed to be on the fringes, and in a crowded market populated by extremely capable products this is not a good place to be. Over the years the Oracle virtualization portfolio has come from a number of different sources, but most recently -- and perhaps most significantly -- the acquisition of Sun has added a lot of depth, particularly in the VDI space. Oracle Virtual Desktop infrastructure is currently at version 3.1 and offers a solution that can integrate with VMware vSphere and Microsoft Hyper-V, as well as Oracle VM. While Oracle VDI offers a basic set of features, it does have some nice integration points with other products in the Oracle family, including the Sun Ray thin client, the Zettabyte File System and Sun Open Storage Portfolio. Regardless of these integration points, however, the fact remains that unless users have a strong relationship with Oracle, this VDI product does not compete strongly in head-to-head comparisons with the market leaders.

RingCube
With the recent release of vDesk 3.0, RingCube now has a desktop solution that takes a place as a VDI contender. The most recent improvements have focused on management and scalability, while the product continues to tackle the issues that plague virtual desktop deployments of almost any size, price and complexity. Using the concept of workspace virtualization, RingCube utilizes Windows Server to host vDesk desktops that are streamed to clients. There's no second instance of the host OS running as part of this workspace, and hence no associated additional license fee. In addition, all of the hardware and host OS abstraction is handled by a very lightweight (less than 100MB) vDesk layer. In many regards this workspace concept is similar to the traditional approach to multiuser computing that helped start Citrix. As such, it has some of the weaknesses inherent to that approach -- but also its strengths.

Administration of the vDesk environment is provided by a Web app that allows an intuitive and flexible policy-based approach toward management. RingCube claims its approach to desktop virtualization enables maximum flexibility, speed and cost savings through centralized management and local execution of the virtual desktop. Some vendors, including VMware, would claim that this isn't pure desktop virtualization, and while this argument has some merit, it's also irrelevant. At the end of the day, if a product or solution meets user needs, the semantics of how it's described or implemented should be of no importance.

Kaviza
Kaviza is another eager newcomer. The company released version 1.0 of its VDI-in-a-box product in early 2009, and by early 2010 had released version 2.2. Clearly focused on small to midsize businesses (SMBs), VDI-in-a-box attempts to remove the complexity and reduce the costs of VDI. VDI-in-a-box utilizes local storage as opposed to a storage area network, which restrains one of the major VDI expenses. As it relates to reducing complexity, VDI-in-a-box utilizes the concept of a virtual appliance called Kaviza Manager (kMGR) to deploy and manage the virtual desktop environment. The kMGR appliance runs on an existing server hypervisor, and, with the newly announced version 3.0, it supports XenServer (and HDX) in addition to VMware ESX/vSphere hypervisors.

Deployment of virtual desktops is managed from the kMGR appliance and offers support for the use of templates as well as integration with Active Directory, which can significantly simplify the deployment process. To access the virtual desktops they create, users require only a browser and a client machine. Kaviza is a solid product with an impressive cost structure that compares favorably to solutions offered by Citrix and VMware.

Unidesk
Unidesk is another emerging vendor with a twist: It's seeking to position itself not as a desktop virtualization vendor, but as a provider of management tools for desktop virtualization. Its product offers some very interesting management capabilities for VDI environments running VMware View and XenDesktop. Unidesk can also manage application-virtualization technologies, including App-V, XenApp and VMware ThinApp. The company has many of the capabilities typically associated with application virtualization, including patching and distribution, and can in many situations do an effective job with that discipline.

Unidesk believes its approach to virtualization management using technologies such as Composite Virtualization and CacheCloud is unique enough to warrant patent protection. It takes a layered approach to virtualizing the OS, in which applications and user personalization data are separated into discrete containers. This Composite Virtualization technology offers a flexible approach to managing virtual desktop and application environments.

With a solid delivery mechanism, CacheCloud, which also facilitates scalability using replication, is a solid product that's straightforward to implement because Unidesk uses virtual appliances that are hosted in users' existing virtual infrastructures. Add in core capabilities such as single-instance storage, thin provisioning and I/O load balancing, and the result is a well-rounded product. The Unidesk approach to virtualization also offers flexibility in adapting to new innovations as they appear, including technologies such as client-side hypervisors. For many companies the attractiveness of a vendor such as Unidesk is its ability to provide management capabilities that don't lock them into to a particular desktop or application-virtualization vendor.

AppSense
AppSense is another vendor of management tools for desktop virtualization, and it offers support for XenDesktop, VMware View and Windows Terminal Server. Currently at version 8, the AppSense Management suite consists of four applications that offer a complete set of tools for managing and optimizing desktop-virtualization environments. The apps are Environment Manager, Application Manager, Performance Manager and Management Center. Each of these tools focuses on a distinct element of the virtual desktop environment, yet they offer seamless integration, and when deployed together they offer a compelling and comprehensive solution to the operational challenges of VDI. Capabilities such as profile analysis, personalization streaming, app personalization, personalization rollback and self-healing offer tangible benefits both in terms of optimizing the end-user experience as well as reducing the administrative overhead associated with VDI. Other capabilities such as storage I/O management, CPU scheduler control and virtual memory management enable significant server optimization capabilities that ensure users maximize their hardware ROIs.

Empowering IT
Citrix, Microsoft and VMware continue to dominate the VDI headlines, but many smaller startups are jumping in and offering a variety of innovative technologies and solutions. We've only considered a small number of possible VDI solutions here, but it's clear the potential size of the market is rapidly attracting many new entrants. The good news for IT departments is that strong competition puts them in a position of power when negotiating with financially challenged young companies. The not-so-good news for IT is, it has a lot of homework to do before starting those VDI negotiations.

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