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Choosing among VDI vendors: Know your needs

There are many VDI vendors and products to pick from, so it's important to know what you need before you settle on which provider you want to use.

Choosing a VDI product is no small task because you must take into account features, setup and maintenance, as well as licensing and ongoing support.

You must also determine which technologies your organization needs. Do you plan to provide stateless desktops? Deliver applications through a virtualization tool? Perhaps you're considering desktop as a service (DaaS).

Clearly, there are plenty of options, and gaining an understanding of the various virtual desktop infrastructure (VDI) vendors and tools will help you make the best possible choice.

The world of VDI

VDI provides a framework for hosting a desktop operating system within a virtual machine (VM) on a server. A user at an endpoint workstation accesses the VM over the network via a remote display protocol that allows the virtualized desktop to be rendered locally.

IT decision makers often turn to VDI because it promises to cut management and support costs by centralizing and simplifying administrative tasks while reducing the resources necessary to maintain individual PCs. User workstations require only a thin client to access their desktops.

But don't confuse VDI with Microsoft's Remote Desktop Services (Terminal Services prior to Windows Server 2008 R2). That provides only session-based access to a server, usually for multiple users.

With a VDI product, users connect to their own desktops and applications, similar to how they would at their local workstations.

Selecting a VDI product

When choosing a VDI vendor or tool, you should consider a number of factors. For starters, the system you choose must support the necessary operating systems. On the VM side, most services can host Windows but often not Linux. Even within the Windows camp, some VDI products can handle XP and Vista, but others cannot. On the endpoint side, VDI tools generally support a larger range of OSes, including Windows, Mac OS, Linux and Unix. Many VDI products now support mobile endpoints, particularly iOS and Android devices.

There are also other factors you'll need to consider. For instance, your clients might require a display protocol other than Microsoft Remote Desktop Protocol. Or you might want to support Web-based access to the virtual desktops. How about support for Microsoft Hyper-V, bidirectional audio WAN or graphics processing unit virtualization?

The key, of course, is to determine exactly which features you must have. Setup and maintenance are the most important considerations, not only to ensure that implementation and ongoing administration are manageable, but also so you get exactly the environment you need. For example, you might plan to implement stateless desktops in which user settings do not persist. Or you might want to go with stateful desktops that save those settings. You might even decide to support both options.

Availability and reliability are also part of the equation. Unlike the traditional desktop model, if a server running multiple virtual desktops is sluggish or goes down, many users can feel the effects. To avoid slow performance or significant downtime, you might need to support capabilities such as load balancing or automatic backups. In addition, your change management strategies should account for how you'll be delivering your applications. For example, if you plan to use a desktop provisioning tool such as Unidesk, you'll have to verify that it will work with your VDI setup.

You should also determine the necessary infrastructure to support desktop virtualization. For instance, do you need both TCP/IP v4 and v6? What level of Active Directory integration do you require? Can you leave your existing infrastructure alone, or will VDI require a substantial investment in resources? And speaking of resources, look carefully at how licensing works. Offerings such as Microsoft VDI are notorious for their complex licensing structures. Be cognizant of the total potential cost, not just for the VDI deployment itself, but also for the OS, business apps and ongoing support.

Above all, understand the provider's financial well-being or lack thereof. When Pano Logic shut its doors in 2012, customers were left standing out in the cold.

An abundance of VDI options

There is no shortage of options to choose from. Citrix XenDesktop and VMware Horizon View have emerged as the industry's top players, and both have a wide range of features. Microsoft VDI remains in the running, especially since the release of Windows Server 2012. But other products are worth considering, too. Dell vWorkspace, Virtual Bridges VERDE and Red Hat Enterprise Virtualization for Desktops are all credible alternatives and may be more affordable than VDI software from the top vendors.

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The VDI market is dynamic, and new approaches to virtualizing desktops come online every day. For example, Citrix now offers VDI-in-a-Box, a pared-down tool for smaller businesses. Other providers are also responding to the changing industry. NComputing vSpace uses OS partitioning and virtualization to create virtual environments. Ericom AccessNow implements HTML5 streaming to deliver a browser-based desktop. And LISTEQ BoxedVDI applies a plug-and-play approach to its virtual desktops. Then there is DaaS, a cloud-based service that lets you offload many VDI headaches, such as provisioning, networking and load balancing. Desktone is perhaps the best-known of the current wave of DaaS providers, which also includes Nivio and dinCloud.

Again, change is the one constant in the industry. VMware bought Desktone, Dell acquired vWorkspace as part of Quest Software, and Oracle purchased its VDI technology from Sun but has since discontinued further development. Consolidation doesn't necessarily translate to success, nor does the inverse approach; just look at Pano Logic.

This all means that a wide range of virtualization options is available, but you need to be aware of the constantly shifting nature of VDI. So if you don't find what you want today, wait a few months and ask around. Before you do anything, however, make sure you know what you need. Implementing VDI software is a significant undertaking. Tread lightly, plan ahead and then proceed with caution.

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