If you are an IT administrator who has been intrigued by all the cost benefits of XenDesktop, then you have probably created a XenDesktop proof of concept environment. Your exposure to XenDesktop has shown the maintenance and security benefits such as centralizing the desktop infrastructure, enhancing the ability to control desktop security, and simplifying the desktop maintenance. Not to mention you now have exposure to the enormous cost savings associated with a complete XenDesktop solution. After some first-hand exposure to all of the perks of a XenDesktop proof of concept environment, you are probably looking to take the proof of concept to the next level and begin the production deployment process.

The biggest obstacle most administrators face when transitioning a proof of concept architecture into a production grade environment is determining how to scale the environment. The Citrix sales team has heard your request for a sizing guide and turned to the Worldwide Consulting Solutions team to help establish recommendations for scaling a XenDesktop environment. The Worldwide Consulting Solutions team built a XenDesktop environment with the Consulting Solutions lab to conduct scalability testing to analyze server and user performance across various test scenarios. Within the lab, each core component of the XenDesktop environment was installed on a dedicated single server (Citrix Provisioning Server, XenServer, and Desktop Delivery Controller). The performance of each server was monitored to determine the optimal number of XenDesktop users for a single server environment. The details of the testing environment and test results have been compiled into the XenServer Scalability document along with the XenDesktop Environment Sizing Guide available at http://support.citrix.com/article/ctx119775.

This XenDesktop Environment Sizing Guide that was created to provide IT administrators with guidance on the approximate number of XenServers, Provisioning Servers, and Desktop Delivery Controllers necessary to scale a XenDesktop environment between a range of 1500 to 250000 XP desktop users. The data for the Sizing Guide was extrapolated based on the single server lab scalability testing conducted for this project.

A XenDesktop environment can be implemented in a variety of architectures and configurations to support the end user demands. Given the variation in end user needs and deployment configurations, the Consulting Solutions team stressed the environment under different circumstances to identify the testing variables that had the most impact on end user performance. The Scalability Results and Analysis section of the document focuses on examining the server performance for each of the three core components under various scenarios and highlights the performance constraints as the upper thresholds of server performance were attained.

As an added bonus, Citrix EdgeSight for Load Testing (ESLT) was used to generate the user load associated with this environment. The specific details of the ESLT test environment and script configurations were documented and are also available in a separate ESLT for XenDesktop Scalability document at http://support.citrix.com/article/ctx119498.