One of the questions you must ask yourself when designing a desktop virtualization solution is understanding the user patterns. This has a direct impact on XenDesktop farm design and scalability with respects to boot up storms and logon storms. Let's take two different examples so you can get a better idea for what I'm talking about. In this scenario, all users logon in the morning and logoff in the evening. There might be some sporadic users working after hours, but for the most part users stay within these working hours. This is a fairly easy scenario, which is why I've started with it. To design your environment, you need to make sure that the boot up storm doesn't overwhelm your environment. You will be starting a large number of hosted virtual desktops and that has a direct impact on your hypervisor of choice, your storage solution and your network infrastructure. You can easily overcome any challenges with a boot up storm in this scenario by using the XenDesktop idle desktops configuration to pre-boot desktops X minutes before the main rush begins (X is based on how many desktops you need up and running before users start connecting). By the time users come online, the system should have calmed down from the boot up storm.
User supported applications account for the largest percentage of applications within the organization. IT does not have visibility into these applications, which makes a move to desktop virtualization difficult without proper analysis. By focusing on Application Assessments, Application Layoffs, and Application Delivery Strategy, the challenge of applications can be overcome in time for the virtual desktop.