Why do migrations of Exchange 2003 mailboxes to Exchange 2007 take incredibly long to connect to the source mailbox?
Posted on 2008-10-27
We've done a migration over the weekend of our domain controllers to Windows 2008 (from 2k3) and also upgraded Exchange from 2003 to 2007.
All went really well (for once!) but....
When using 2007 Exchange Management Console to migrate users (I've got over 9000 users to move) I can use the migration wizard, everything goes through fine, but when it begins to migrate it takes an absolute age to connect to the source database. If I migrate 1 user at a time it connects almost instantly, but when migrating 100 users, it takes over 1hr to connect. Once connected the 4 streams run off and the migration is as quick as I'd expect.
Any idea's folks? The mailboxes I'm migrating are small accounts (school kids mailboxes, all with a limit of 5mb) so size isnt really an issue...