There are several different models for virtual desktop usage, but the most popular is the centralized, volatile desktop model where desktop virtual machines (DVMs) are created on the fly as users log into the system. An endpoint device is no longer the core machine users must rely on. Rather, it's just a device with a Remote Desktop connection ability.
Because of this, you no longer need to spend an inordinate amount of resources managing the endpoint. Instead, you should focus on managing and locking down the virtual desktop image that the users actually rely on to perform their work. But, to properly manage virtual desktops and give each user the very best experience, you must be able to categorize your user bases and assign the appropriate virtualization method to each target user audience. Here are the three audience types you will need to work with:
- The Basic Productivity Worker requires fewer application types than the other two. Normally, this user requires nothing more than the basic operating system along with productivity applications such as Microsoft Office. They will have intermittent usage that will be primarily text-based. They will have limited mouse use and limited printing requirements. This desktop user type will log in at distributed times and create a variable workload on centralized host servers. The ideal system for this worker type is a standard virtualized desktop.
- The Knowledge Worker requires a more powerful centralized desktop because this type tends to run multiple business and productivity applications at the same time. Knowledge Workers use applications that are richer in graphics and therefore require more memory per user. They also tend to be logged in at the same time. If your DVM is properly designed, then it should also meet the requirements for most Knowledge Workers, including at least basic graphics tools along with the productivity suites within the base DVM image. The virtual desktop they use will need to provide a richer graphical experience and more resources per VM.
- The Rich Desktop User most likely runs multiple compute- and graphics-intensive applications at the same time. Engineers and traders are examples of this type of user. They often require specialized engineering or trader peripherals and often require multiple displays connected at the same time. They also need high-end graphics resolutions, something most host servers lack. For this reason, it is often best to solve these users' requirements with blade PCs -- PCs that are centrally-hosted in data centers in blade enclosures -- instead of virtual desktops, though virtual desktop capabilities are improving. For example, Microsoft acquired Calisto Technologies in 2008. Calisto specializes in improving the Remote Desktop experience for end users through 3-D acceleration. This technology will be embedded in Windows, which should improve the Remote Desktop connection users experience when they connect to virtual desktops. VMware is also working on improving the graphical experience for DVMs with the upcoming VMware View, which will provide anywhere access to a user's desktop virtual machine. In these cases, the blade PC may no longer be required.
Each user type requires a different virtualization method. However, as pointed out earlier, centralizing the desktop is not always the best solution. Table 1 describes the different models that are available for reducing the cost of distributed desktop computing through virtualization. It lists several solutions, including technologies such as Presentation Virtualization, which is really server-based computing, as well as PC Blades. This table also outlines the impact each solution has on the end user experience.
Table 1. Comparing distributed versus centralized desktop virtualization
| Feature |
Free VM engine on local desktop |
Encrypted Local VM |
Advanced Local VM Engine |
Presentation Virtualization |
Centralized Virtual Desktops |
PC Blades |
| Graphics |
Fair |
Fair |
Fair |
Fair |
Good |
Better |
| Video |
Fair |
Fair |
Fair |
Fair |
Fair |
Better |
| Performance |
Average |
Average |
Average |
Average |
Better |
Best |
| Redundancy |
Poor |
Poor |
Poor |
Good |
Best |
Good |
| Printing |
Good |
Good |
Good |
Poor |
Good |
Good |
| USB |
Fair |
Fair |
Better |
Poor |
Fair |
Best |
| AD Integration |
Good |
Good |
Good |
Good |
Good |
Good |
| Application Compatibility |
Good |
Good |
Best |
Average |
Best |
Best |
| Management |
Poor |
Better |
Poor |
Average |
Best |
Best |
| Deployment |
Poor |
Good |
Poor |
Average |
Best |
Good |
Rely on this table to determine which solution best fits your own users. Categorize them within the three core user types, and then identify the solution you need to apply to their needs. This will help you properly understand the desktop virtualization technology you need to put in place. In the end, you may have to implement a hybrid solution combining desktop virtualization and blade PCs to best meet your users' needs.
Table of Contents
Tip 1: Verify device support in your hypervisor
Tip 2: Identify desktop virtualization audiences
Tip 3: Prepare and protect user profiles before virtualizing your desktop
Tip 4: Use application virtualization before moving to VDI
Tip 5: Lock down systems by switching to a VDI technology
About the Authors: Danielle Ruest and Nelson Ruest are IT futurists specializing in IT infrastructure optimizations and IT efficiency. Danielle is Microsoft MVP in Virtualization and Nelson is Microsoft MVP in Windows Server Failover Clustering. They are authors of multiple books, including the Windows Server 2008, The Complete Reference for McGraw Hill Osborne and the MCITP Self-Paced Training Kit (Exam 70-238): Deploying Messaging Solutions with Microsoft® Exchange Server 2007 for MS Press. Their upcoming book will be Virtualization: A Beginner's Guide from McGraw Hill Osborne. They presented on Hyper-V at the Data Center Decisions conference in Chicago in October. They are also delivering a virtual tour across the U.S. Feel free to contact them at infos@reso-net.com for any comments or suggestions.
