A few weeks ago Citrix announced their plans for XenDesktop 5, their latest desktop virutalization product. We published a detailed analysis of what's new and what you need to know, although at that time we hadn't actually put our hands on the product. Fast forward to today... we still haven't actually used XenDesktop 5 yet, but there's one thing that a lot of people are talking about that's worth mentioning: It looks like there will be no simple migration path from XenDesktop 4 to 5. So what's that mean for folks who are just in the planning, proofing, or piloting phase for XenDesktop 4. Do you pause your project for six months? Do you move ahead now, knowing you'll have a painful migration soon in the future?
Why is there no migration path?
Remember that one of the big new features of XenDesktop 5 is that Citrix is finally moving away from the "IMA" architecture that's powered their products since the days of MetaFrame XP back in 2001. (IMA is the whole back-end management subsystem that includes the configuration databases, the communication and control services, the administrative interfaces, and the server-to-server communication protocols.) IMA was designed when a "big" farm had a few hundred MetaFrame servers. But in today's XenDesktop world, each desktop is like its own single-user MetaFrame server (at least as far as IMA is concerned), so a 10,000 seat XenDesktop environment is probably 50x bigger than Citrix ever imagined was possible when they were designing IMA.
Make no mistake: Moving XenDesktop off of IMA is a very, very good thing. And we've known this was coming for a long time. Citrix recently said they've been working on the new architecture for "years," and Citrix's chief software architect Brad Pedersen mentioned it when I interviewed him back in 2006.
Unfortunately this completely new back-end architecture (which was codenamed "storm" internally) means that there's no easy way to migrate from XenDesktop 4 to 5. All of your farm configuration, your desktop configuration, your groups, your admins, your security, your policieis, your servers--everything--will need to be rebuilt from scratch.
This isn't something that's new to Citrix customers. The move from XenApp 5 to XenApp 6 was similarly harrowing as XenApp 6 requires Windows Server 2008 R2 which is x64-only. (Ironically XenApp 6 is still based on IMA. If Citrix bases XenApp 7 on storm, then will customers have no migration path again?)
What's the impact of no migration path?
The real question is whether a lack of technical migration path will really impact customers? A lot of folks like to keep their environments "clean" and don't really trust upgrades, so there's a good chance that most people would have built a parallel environment anyway.
It's also worth considering that not everything will be different in XenDesktop 5. For example, anything having to do with the actual desktop VMs themselves--the images, the applications, the user environment, the provisioning, etc.--can be easily moved from the old environment to the new.
The big question, again, is what this means for customers who have not yet fully deployed XenDesktop 4. Do they wait? Do they continue with the intention of redoing the back-end in a few months? Do they continue with XenDesktop 4 and plan to skip XenDesktop 5? (And if so, do they feel stupid for having Subscription Advantage?)
What does this mean for you? Does a lack of migration path change your immediate plans, or is it business as usual?