Desktop virtualization promises to save enterprises from rising data center costs and management headaches. IT administrators, however, have had to contend with immature technology, inconsistent terminology and executive and user reluctance. Fortunately, you can get the most out of virtualization by assembling a toolbox of assorted technologies.
Capacity planning and sizing
One of the first questions to ask any VDI vendor is, "How many users can I fit on a server?" Invariably, the answer is "it depends," which is as maddening as it is correct.
Fortunately, many tools can help you get an idea of what resources people are using. Some of those tools can also help you translate that information into something relevant to VDI. A few others even go so far as to take your costs, combine them with industry-standard costs, and present a detailed cost model for your migration.
Lakeside Software, Liquidware Labs and eG Innovations are the top three vendors in the capacity planning market, but other companies sell similar software and new products are being released all the time. Almost all of them claim to help with capacity planning and sizing, but these three vendors have products designed specifically for that purpose.
Load testing requires a different methodology than capacity planning and sizing. The basic premise is that load-testing tools generate a workload in an environment, stressing it until it breaks or certain thresholds are met. These tools are highly customizable so that you can emulate your actual workload, rather than just a bunch of common scripts. A lot of work goes into setting up a valid, useful load test and a few products can make the job a lot easier.
The Scapa Test and Performance Platform for BMC Remedy, Login Virtual Session Indexer (VSI) and Citrix EdgeSight for Load Testing are the top three products on the market today (in no particular order), although there are others. Login VSI, created by Netherlands-based Login Consultants, was initially developed as a tool for the company's consultants to load-test their customers' environments. It has a reputation as one of the most accurate and useful load-testing tools on the market. Scapa and Citrix EdgeSight for Load Testing also have proven track records and useful features for creating random, real-world load-test scenarios.
These tools are often used with other performance monitoring tools. VSI, for instance, creates the loads and reports on them, while the other tools can be used to put everything into the same monitoring "language" to compare the load-testing results to the actual environment.
User experience monitoring
This capability tends to get lumped in with capacity planning, sizing and load testing, but the user experience is a separate entity. There is some overlap, because without an appropriately sized and loaded environment, the user experience will suffer. Still, the user experience is the most subjective of these examples and it needs to be treated differently.
Visibility into the VM and the endpoint is critical in measuring the user experience, because you need as much information as you can get to diagnose complaints about slow typing or bad video-playback speed. Tools that don't provide enough visibility may fall short.
If you have the foresight to monitor performance before you move to VDI, you'll likely want to continue doing so after you move.
While not every vendor offers a compelling migration product, many do sell tools tailored for VDI performance monitoring. Some can also monitor other aspects of IT, so a deliberate choice could result in just one performance monitoring solution for your entire company. Even if you're not quite so fortunate, you could still find a tool that will monitor all of your desktop virtualization systems.
Sometimes, the in-box solutions that come with your VDI platform are enough. Tools from companies such as Xangati can monitor the data center components behind your VDI environment, but offer little insight into the VMs. Both Liquidware Labs and Lakeside take their capacity-planning products to the next level by offering versions that are meant to be used beyond the initial capacity planning or migration project.
ABOUT THE AUTHOR:
Gabe Knuth is an independent industry analyst and blogger, known throughout the world as "the other guy" at BrianMadden.com. He has been in the application delivery space for over 12 years and has seen the industry evolve from the one-trick pony of terminal services to the application and desktop virtualization of today. Gabe's focus tends to lean more toward practical, real-world technology in the industry, essentially boiling off the hype and reducing solutions to their usefulness in today's corporate environments.
This was first published in October 2011