That was the last question I heard at Citrix Synergy, to which the presenter said “That’s a good question!”
Initially, my answer to that question is you should stream the OS to a desktop whenever possible because I like to manage as few things as possible. If I can stream an image to a desktop, I only need to manage the image, not the desktops individually in regards to Windows updates, application installations and updates, anti-virus, etc, etc.
During his first Synergy Keynote, Mark Templeton discussed the “Mathematics of Complexity”. Speaking on an internship with Chrysler (if I remember correctly) in the 1970s, top executives with Chrysler determined Japanese cars were gaining in popularity and achieving higher reliability than American cars because they had fewer parts. Mr. Templeton then stated that if a car is built with 100,000 parts that are each 99.9% reliable, then total system reliability would be right at 80%. If a car is built with 50,000 parts, and each part is 99.9% reliable, then total system reliability would be over 90% reliable.
That’s the reason I like streaming to desktops, I’m eliminating parts and decreasing complexity.
So, when do you stream to virtual desktops? The most obvious reason may be to allow remote connectivity to your corporate image through an Access Gateway.
Second, the ultimate goal is to minimize the number of images to manage. If your environment, has many different desktop hardware platforms, then streaming to the desktop may force you to create more images than you wish to manage. In that case, stream to virtual machines hosted on your virtual infrastructure and direct end users to your XenDesktop Web Interface. During subsequent desktop refreshes, consider using thin clients with built-in support for XenDesktop or identical (or close to identical) desktops and create a common image.
Finally, and similarly, streaming to virtual machines would be ideal if you switch to a BYOC (Bring Your Own Computer) program. This program, implemented by Citrix, could become a popular model moving forward as it helps an organization cut desktop support costs and gives employees the freedom to choose their own desktop platform. With this model, an employee would be given XX dollars to purchase a laptop with which they would connect to a corporate OS image thru the XenDesktop Web Interface in order to run the applications required to do their job. The company saves because IT is not responsible for the maintenance or support of the desktop, IT is “only” responsible for providing the image, the applications, and the users personal data.
Those are my thoughts on when to stream to physical and virtual machines. I’d love to hear yours.