The pros and cons of using virtual desktop infrastructure

Many organisations continue to run Windows XP on many or all of their desktop PCs, either because migration typically requires costly hardware upgrades, time-consuming transfers of settings, and user retraining, or because there’s simply no compelling reason to move users to a new OS and the new application software that goes along with it. In some cases, both justifications apply.

But when you consider that Microsoft has already stopped issuing non-security hotfixes for Windows XP and will end all support for the OS in 2014, that strategy won’t be tenable for much longer.

Virtual desktop infrastructure (VDI) utilises server hardware to run desktop operating systems and application software inside a virtual machine. Users access these virtual desktops using their existing PCs. This not only eliminates the need for workstation hardware upgrades, but also enables the user to switch between operating environments, such as Windows XP and Windows 7.

What’s more, VDI renders administrative and management tasks much easier, because every attached workstation can use the same image. Install OS and application software updates and patches to the one image, and every desktop system using that image is automatically updated and patched.

VDI offers clear benefits, but there are two sides to every coin. Here’s a brief look at the pros and cons of using virtual desktop infrastructure:

1. Every desktop user can utilise the same image.

Pro: Having each user utilise the same image - the operating system as well as the installed applications - reduces administrative and support costs.

Con: You’ll need a unique image for each user who requires a different set of applications, needs to save personal settings, or requires the freedom to install their own applications. This will rapidly multiply storage consumption on the VDI server.

2. Processing moves from individual workstations to a VDI server.

Pro: There’s no need to upgrade numerous PCs to meet the new OS’s minimum hardware requirements.

Con: VDI will require a major investment in server hardware, and possibly in storage and network infrastructure. The total cost of the server hardware, storage, and network equipment might exceed that of procuring a basic PC for each user.

3. Hardware costs can be more easily managed, since almost everything will reside in the data center.

Pro: Instead of buying a raft of PCs that will be scattered around the office - or even outside the office if you’re supporting a mobile workforce or employees who work remotely - you'll acquire one premium system with redundant power supplies, a UPS, high-performance storage, and high-bandwidth networking that will deliver capable hardware to all users equally.

Con: Procuring one big server means a large initial outlay, versus inexpensive PCs that can be acquired in stages or upgraded a few at a time. If that one server goes down, every user relying on that machine will be unable to work. If a single PC goes down, only one user is impacted.

4. Maintaining a single OS image can reduce management and support costs.

Pro: Install applications, patches, and drivers once, and every user relying on that image benefits from the update.

Con: Administrators will need to learn the VDI software’s capabilities and limitations. Accommodating users who require unique applications or their own personalization settings can result in image proliferation, which can end up being more difficult to manage than operating separate workstations.

5. When you encounter problems, you’ll generally have just one system to troubleshoot.

Pro: Problems can generally be resolved from within the data center; there’s no need to run out to the actual PCs. Since images can usually be accessed from any connected workstation, a user experiencing hardware trouble on their usual PC can simply go to another workstation and access their data and applications.

Con: Server-side problems can affect multiple users - everyone using that server or that image. For that reason, it’s a good idea to set up redundant servers as a failsafe.