Decrease exchange 2007 to 2010 cross-forest migration downtime RRS feed

  • Question

  • Hello all

    I need to cross-forest migrate Exchange 2007 to 2010.
    All mailbox databases ~2Tb+

    By my current plan I will use script to start remote new-moverequest with SuspendOnComplete flag for all mailboxes. (Estimate moving time 27 days!!!)
    When all mailboxes will be almost complete i'll finish move requests at the same time. 

    Unfortunately, it will take up to 24-36 hours to complete move requests and copy all difference between source/dest mailboxes. And it means that i'll get service downtime for some users. Users will slowly disappear from old address book and appear in new.

    Does anybody know any other variants of migration?

    Maybe i can create new empty mailboxes for all users in new domain at one moment and start to copy mailbox items from one mailbox to another.
    Or dismount mailbox database from in one domain, copy it and mount in another.

    I hope i miss some ways...

    Any ideas?




    Friday, February 4, 2011 1:12 PM


  • Actually you can keep folks in both GALs. Take a look at using PrepareMoveRequest ahead of time for each user. That will provision a Mail Enabled User for each user in the new forest's GAL. As you complete move requests, the MRS will convert users in the source forest to mail enabled so they will stay in the GAL and simply route mail over to the new Exchange org. This will also enable free/busy to continue working between orgs.

    If I were you I would stage this. By the time you get to the end of Day 27 you're going to have massive deltas on the original users which is going to make the final sync take a long time. Break it up in manageable chunks and you'll be much better off. You can run moves during the day and unsuspend them at night.

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    • Proposed as answer by Gen Lin Monday, February 7, 2011 7:51 AM
    • Marked as answer by Gen Lin Friday, February 11, 2011 3:50 AM
    Friday, February 4, 2011 8:57 PM