According to expert Brian Madden, two common reasons virtual desktop infrastructure projects fail are because administrators are too quick to create non-persistent desktops, and because they think persistent desktops are essential.
If that sounds contradictory, Madden explained why to attendees during his presentation at TechTarget's Storage Decisions Conference in New York: Advancements in virtual desktop technology (VDI) are changing the way VDI works faster than the ideology of many administrators.
Persistent versus non-persistent VDI is one of the most important decisions that virtualization administrators need to make when carrying out a VDI project. Persistent VDI allows users to customize their desktops and any changes they make will be saved after a restart -- the more attractive option from the user's perspective. When using non-persistent VDI, all desktops share the same disk image -- when users make changes to their desktop, the changes will not persist after a restart. This is typically more attractive to administrators because a single disk image allows for easier management.
During the presentation, Madden admitted that even though non-persistent VDI is easier to manage in the long run, he has been a proponent of persistent desktops since VDI became popular in 2006.
"The difficulty comes when you can only virtualize 75% of your applications. What about the apps you can't virtualize? What about user-installed apps? What about user settings? Some users are going to need admin rights, and now I have to figure out office plug-ins, browser plug-ins, and at the same time as all of this I'm going to VDI, so it's all different in the way it connects. When all this happens in these environments, it's tough," he said.
Madden explained that due to the complicated combination of starting a VDI project and creating non-persistent desktops, it's best to start out persistent and move to non-persistent VDI after desktops have been virtualized.
However, he also expressed that this long-held belief is changing due to advancements in VDI and storage technology. "Today's storage absolutely can support fully non-persistent disk images," he said, citing the fact that most applications are now virtualization-compatible, and that today's users are less concerned with having the ability to download personal apps.
"As a VDI guy, I finally have the option where I don't have to make all storage persistent. So now that we can support persistence [for a reasonable cost] we don't have to," Madden said.