BES co-existence during an Exchange 2003 to Exchange 2007 migration

By ENow ESE contributing author, Kevin Wilson

Most of us have read the RIM article describing required steps when migrating BES from Exchange 2003 to Exchange 2007. The problem is the article assumes you can migrate all BES users to Exchange 2007 in one quick shot rather than dealing with a period of ‘co-existence’. Essentially the article explains how to reconfigure your BES to work with Exchange 2007 but you lose compatibility with Exchange 2003 in the process so you need to make sure you can get all BES user mailboxes moved over to Exchange 2007 quickly in order to use RIM’s instructions. For most organizations this isn’t feasible so they are faced with a period of co-existence.

A typical migration scenario is:

• A single Exchange 2003 organization in the same Active Directory domain
• One or more Exchange 2003 BE servers
• One or more BES servers
• One or more Exchange 2007 mailbox role servers
• All users to be migrated from Exchange 2003 to Exchange 2007

In order to co-exist, that is, in order to allow the mailboxes of some BES users to reside on an Exchange 2003 server and at the same time have others reside on an Exchange 2007 server, there are a few simple requirements and steps to follow:

1. Before moving any BES user mailboxes, set the required permissions for the BES service account (i.e. BESADMIN) on the Exchange 2007 servers. For more information, see KB12483.
2. Restart all Blackberry services (KB04789) so that the BES service account refreshes and inherits its new permissions.
3. Ensure all Exchange 2003 and BES servers are running the Exchange 2003 SP2 version of the Exchange System Manager (version 6.5.7638). See KB14502 for upgrade instructions.
4. Now, go ahead and move some test BES user mailboxes from Exchange 2003 to Exchange 2007 and thoroughly check BB functionality after the move (i.e. mail flow, calendaring and appointments etc.) and also confirm the BES user mapi profile automatically updated to the Exchange 2007 server via the Blackberry Manager (run the HandheldCleanup tool if the mapi profile is slow to update). Repeat this process for test user accounts on each of you BES servers and from each of your Exchange 2003 servers to ensure all scenarios have been tested.¹
5. The next step is to migrate a real Blackberry user or two. Test user migrations are great but in order to really feel confident about your migration process you need to migrate a real user and let them live in co-existence for a period of time (at least a week). During this time, communicate with this user daily to see if there are any issues (give them a check list of things to test to ensure all functions are covered).
6. Assuming all has gone well with your testing, you’re ready to start moving the rest of your BES users which brings us to the next question, should I move them in slow batches or all at once. While the above tests should have proved that co-existence works I always recommend that you migrate all BES users at the same time (or in batches as quickly as possible). There is always the chance for unforeseen compatibility issues but you can mitigate the impact to the BES users if the coexistence period is limited to as short a period a time as possible (in other words, try and migrate all BES user mailboxes in a single weekend if possible).
7. The last BES mailbox to be moved to Exchange 2007 would be the BlackBerry Enterprise Server service account mailbox (i.e. BESADMIN). After this account is migrated, reconfirm the required permissions are set on the Exchange 2007 servers as per KB12483.
8. Now that all BES user mailboxes are migrated, stop the all BES server services.
9. Using an account that has full Exchange permissions, uninstall the Exchange 2003 System Manager from your BES server.²
10. Download and install ‘Microsoft Exchange Server MAPI Client and Collaboration Data Objects 1.2.1’ onto your BES server and then reboot the server.
11. After the server restart completes log back onto the BES server as ‘BESADMIN’ and go to "Start ->Programs -> BlackBerry Enterprise Server ->Edit MAPI Profile" and ensure you can resolve the BESADMIN mailbox on the Exchange 2007 server (migrated in step 7 above).
12. Then, go to “Start -> Programs -> BlackBerry Enterprise Server -> BlackBerry Server Configuration -> BlackBerry Server Tab -> Edit MAPI Profile" and ensure you can resolve the BESADMIN mailbox on the Exchange 2007 server (migrated in step 7 above).

Now that you have the process defined, it is time to move on to defining the migration schedule.

Every organization’s needs are different so be sure to take into account any special requirements.

It may be helpful to produce a list of BlackBerry users by department and server. Depending upon if you utilize the user’s Active Directory user properties, security groups, or OUs to organize your BES users ,this may be a consuming task. It is necessary to do this in order to have a good understanding of how devices are currently deployed and to determine when they will be migrated to minimize any impact. I like using a tool called Mailscape that makes finding this information very simple and easy.

posted by Kevin Wilson at 9:20 AM 2 Comments