You can't migrate to Exchange 2013

Yet -- Microsoft hasn't delivered all the pieces needed to make your environment compatible with the new server

It's been an amazing year for Microsoft releases: Windows Server 2012, Office 2013, SharePoint 2013, Lync 2013, and Exchange 2013, to name the big ones. I've previously covered the key new features in Exchange 2013, and I'm sure many of you want to upgrade to it. But you can't. You simply can't.

Let me explain.

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To transition your Exchange 2007 or 2010 environment to Exchange 2013 requires that you upgrade your Active Directory schema with the new changes for 2013. Then you need to install Exchange 2013 itself, install your certificates, move the existing CAS namespace to the new CAS server, and make a bunch other adjustments. But none of these are why you can't upgrade to Exchange 2013.

The problem is with Exchange 2007 and Exchange 2010 -- more precisely, in coexisting with them. Exchange 2007 needs a special roll-up to work with Exchange 2013, and Exchange 2010 needs Service Pack 3. Even if your goal is to fully replace Exchange 2007 or 2010 with Exchange 2013, you need the new and old versions for at least a transition period. Neither update exists yet, so you can't migrate to Exchange 2013.

Why would Microsoft release a new product but not provide the pieces needed to migrate legacy servers to that new product? I wish I knew. Whatever the reason, you're left mapping out plans that you can't execute until these missing pieces are released -- by July 2013, according to Microsoft's Exchange team.

But what if you're now using Exchange 2003? Sorry, but Microsoft has no migration path from Exchange 2003 to Exchange 2013. You either will have to migrate twice, once from Exchange 2003 to Exchange 2007 or 2010, then again to Exchange 2013, or you'll need to find a third-party migration tool that can do the jump in one step. (I'm not aware of any such tools so far.) When you're preparing the migration, be sure to run Microsoft's Web-based Deployment Assistant to see the current recommended steps for your configuration.

But even after there is a technical migration path, I wouldn't be so quick to take it. You might consider waiting a bit longer for Exchange 2013 SP1 to arrive (no date has been set). Microsoft's service packs tend to make the core products more fully baked, add new features, and fix others.

One example of how waiting might benefit your company has to do with Exchange 2013's new Managed Store capability, where the number of mountable databases per Exchange Server has been reduced from 100 to 50. That's still a large number of databases that can be mounted from one Exchange Server, but if you're mounting more than that now, you'll have to purchase additional hardware to accommodate all the databases when you switch to Exchange 2013. It's possible, although no promises have been made, that Exchange 2013 Service Pack 1 will bring the number back up to 100 mountable databases. I think it's worth delaying an Exchange 2013 to find out.

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