Top 10 Things to Consider in 2011 Before Your E2E Migration

As we enter 2011, many of you are considering a migration from Exchange 2003 to Exchange 2010. If you read Karl Sand’s Good Migrations blog post on Friday, you already know that the leap from Exchange 2003 to Exchange 2010 will be quite an undertaking. Why? Because the process of upgrading from Exchange 2003 to Exchange 2010 is more of a migration project rather than an upgrade.

With that said, below you’ll find a list of the top ten key factors that you should take into consideration as you embark on your Exchange 2010 migration/upgrade:

  • As we enter 2011, many of you are considering a migration from Exchange 2003 to Exchange 2010. If you read Karl Sand’s Good Migrations blog post on Friday, you already know that the leap from Exchange 2003 to Exchange 2010 will be quite an undertaking. Why? Because the process of upgrading from Exchange 2003 to Exchange 2010 is more of a migration project rather than an upgrade.

    With that said, below you’ll find a list of the top ten key factors that you should take into consideration as you embark on your Exchange 2010 migration/upgrade:Exchange 2003 Users are Offline During Mailbox Migrations
    : If you are using a Microsoft supported mechanism to migrate your mailboxes from Exchange 2003 to Exchange 2010, your users will be unable to send/receive new email during the transfer.Mailbox
  • Moves are Asynchronous: Unlike Exchange 2007, mailbox moves are simply “requests” which get executed as “slots” become available. Any moves exceeding the number of available slots are queued. This can make it difficult to schedule a particular mailbox to migrate at a specific time.
  • Destination Site Client Access Servers Perform the Actual Data Migration: Regardless of where you execute the PowerShell commands from, a CAS in the destination site is randomly chosen to shuttle the data from the source to the target database.
  • You Can Control the Rate at Which Mailboxes Move: Each CAS maintains an editable XML file called “MSExchangeMailboxReplication.exe.config” which governs the throttling settings for the data transfers. While most of these settings are fine for typical environments, you may want to increase the “MaxActiveMovesPerTargetMDB” from the SP1 default of “2” to “5”.
  • Outlook 2003 Will Work With Exchange 2010: By default Exchange 2010 will only communicate with clients that connect securely. If you wish to use legacy Outlook 2003 clients, you should deploy a GPO to force those clients to enable encryption to the server. In this case, you will also want to replicate your Schedule+/FreeBusy data to Exchange 2010.
  • A Global Catalog is Required in Each AD Site: Unlike Exchange 2003, a GC is required in each site where an Exchange 2010 server will be located. Be sure to take this into consideration during your design.
  • Lack of RUS May Impact Existing Provisioning Tools: If you have an automated mailbox provisioning tool, you will want to create a test case to ensure it remains compatible with the RUS-less Exchange 2010. You may need to retain an Exchange 2003 server if any of your apps or processes require the RUS, or certain depreciated connectors (GroupWise, X.400, etc.).
  • ActiveSync Devices May Fail: Should mobile devices fail after integrating an internet facing 2010 CAS into your environment, you should investigate KB937031 for an Exchange 2003 patch. While on the topic of mobile, your Blackberry users may need several hours before BES detects the mailbox move. Plan accordingly.
  • OWA 2010 Can Service OWA 2003 Users: If your users have committed your existing OWA URL to memory, you should know that OWA 2010 can successfully direct users to the right server, during your migration project. Be sure to enable forms based authentication, and use the “Set-OWAVirtualDirectory -Identity “Ex2010\OWA (Default Web Site)" -Exchange2003URL https://legacy.contoso.com/Exchange” command to configure it. 
  • Use the Microsoft Exchange Remote Connectivity Analyzer: When making critical changes to your external DNS, you can quickly use the Connectivity Analyzer to verify the integrity of your changes. You can access this tool at https://www.testexchangeconnectivity.com/

I certainly hope this list is helpful. Of course if you’d like to know how Binary Tree can assist you in ensuring that your Exchange 2003 to Exchange 2010 upgrade/migration is a success, please don’t hesitate to contact us. Also, for more information on Binary Tree’s E2E Complete Migration Solution, click here. See you in 2011!

- Val