If you’re planning an Exchange 2010 migration, you’re probably familiar with the term ‘you had me at ehlo’ and various books with a blue/black cover.

But there’s no substitute for experience, and although no two migrations are ever the same, here’s my top list of my ‘surprises’ from an email migration running into the tens of thousands of mailboxes. You may never encounter them, nor may I again, but maybe, just maybe it’ll save you a 1AM conference call…

1) You really, really need to understand your user profile

Don’t rely on the Microsoft defaults provided with the Calculator. You have, I assume, an Exchange environment already, and that you can go out there and measure. Once you have these stats, you might find that the idea of hosting 20,000 mailboxes on the old P3 laptop you’ve found in the corner of the office isn’t going to fly. Or more likely, you will find that your initially generous assumptions about deleted item retention and mailbox recovery might need to be trimmed a bit, and log file disks and required IOPS bumped a little. Or a lot.

2) Firewalls need love, too.

Traditionally, a firewall would be put between the bad guys on the internet, and the internal network, and perhaps some partner organisations. However, in a diverse network arrangement, it’s quite common that there might be a firewall between your internal client machines and your CAS’. Your firewall guys will be wise to the fact that a ‘traditional’ outlook client connection uses MAPI based on RPC, in which we’ll look to use TCP/135 and high ports. So, bang the protocols and destination IP addresses in the firewall, and away we go?!

So based on the information you just read, I think you want to head on over to, “What your mother never told you about Exchange 2010 Migrations”

Run these commands in Power Shell to fix. Best to just copy and paste into Powershell

Import-Module ServerManager

Add-WindowsFeature NET-Framework,RSAT-ADDS,Web-Server,Web-Basic-Auth,Web-Windows-Auth,Web-Metabase,Web-Net-Ext,Web-Lgcy-Mgmt-Console,WAS-Process-Model,RSAT-Web-Server,Web-ISAPI-Ext,Web-Digest-Auth,Web-Dyn-Compression,NET-HTTP-Activation,RPC-Over-HTTP-Proxy -Restart

or….

In Server Manager->Features->Add Feature, select to install the “RPC over HTTP Proxy” feature.

Either or will fix the blank Outlook Web App Issue.

-NS

Update 2/11/2011: Windows 2008 R2 SP1 includes the required hotfixes listed in this table — 979744, 983440, 979099, 982867 and 977020. If you’re installing Exchange 2010 SP1 on a server running Windows 2008 R2 SP1, you don’t need to install these hotfixes separately.

If you are wondering what each hotfix did you can check here.

The main thing I am trying to point out is that if you are installing Exchange 2010 with Service Pack 1 on Windows Server 2008 R2 SP1, you would only need the Microsoft Office 2010 Filter Packs.

The just-released Exchange 2010 SP1 requires the new Microsoft Office 2010 Filter Packs. SP1 setup registers the IFilters with Windows Search. You’re no longer required to run a shell or VBS script, or manually create registry entries to register the Office 2010 IFilters.

Let’s give Microsoft a big hand, for attempting to make life easier on us!

-NS