How to migrate from Exchange 2007 CCR to Exchange 2010 DAG on existing hardware (Part 2)

If you would like to read the first part of this article series please go to How to migrate from Exchange 2007 CCR to Exchange 2010 DAG on existing hardware (Part 1).




After having discussed the way to prepare the Exchange Server 2010 Service Pack 1 deployment in your Exchange 2007 CCR based deployment in the first part of this article, we now need to discuss how to go on with further steps and finish the deployment.


Install Exchange 2010 Mailbox Server Role


At first we need to install Windows Server 2008 R2 on the former Exchange Server 2007 server. After this we will install Exchange Server 2010 SP1 with the following roles on the machine:



  • Mailbox Server Role
  • Client Access Server Role
  • Hub Transport Role


The roles “Client Access” and “Hub Transport” need to be moved after the decommissioning of the Exchange 2007 server environment. Then the existing Hub Transport and Client Access servers based on Exchange Server 2007 are not needed anymore and can be removed from the organization.


Configure DAG


Now we need to configure the Database Availability group – at the moment – with only one Server. The DAG configuration is well described at:




Configure Client Access and Hub Transport


To make sure that the new mailbox server can be contacted from the clients and that routing is impossible, we now need to transfer the Exchange 2007 Client Access and Hub Transport Server configuration to their Exchange Server 2010 pendant.


Moving Mailboxes


After having all mailboxes moved from Exchange 2007 to Exchange 2010 SP1 to Exchange Server 2007 including the internal Exchange mailboxes, we can uninstall the last Exchange 2007 Mailbox CCR node and finally uninstall the existing Exchange Servers with the Client Access Role and the Hub Transport role.


This means we now have a native Exchange 2010 Service Pack 1 Organization, but need to make sure that no fragments of Exchange Server 2007 are left in Active Directory. This can be done by manually researching the “Configuration Partition” of Active Directory for entries that include the old Exchange Server 2007 names. Before deleting them manually, which is the only way to get rid of them, you should create a System State Backup of the Server to have a roll back if things are missing because of having deleted false entries.


Installing the second DAG member


After a clean installation of Windows Server 2008 R2 Enterprise Edition on the formerly existing Exchange 2007 box, we need to install Exchange Server 2010 SP1 Mailbox Server Role in the corresponding version that already exists as the first Exchange 2010 Server.


Now we need to join this server to the existing DAG, this can be done quite easily using the DAG container in the Organization Configuration of the Exchange Server 2010 System Manager. Afterwards, we need to prepare the most time consuming task of creating the mailbox database copies from DAG Server 1 to DAG Server 2. Depending on the size of the mailboxes and the server and network performance this tasks may take from some hours to some days. You may find out that there are some databases in your Environment that do not have proper database states. If this is the case, you will need to check this using the well-known recovery tasks of Exchange. In the case the database copy task of some mailboxes does not finish successfully, you have a way to copy the database files, log files and checkpoint files manually from one server to another with stopped Exchange Information Store services on the source Exchange Server.


Transferring the Client Access and Hub Transport Server Role


After decommissioning the last Exchange 2007 mailbox server, we do not need the Hub Transport and Client Access Server anymore. So we can uninstall and reinstall them with Windows Server 2008 R2 and the corresponding Exchange Server 2010 server roles. Due to the configuration lives in Active Directory, we only have to transfer some of the settings to the new role members. Now, having Exchange Server 2010 based dedicated Hub Transport and Client Access Server roles, we need to uninstall the hub transport and client access server role from the first DAG member, where it has been installed for the migration time.


Finalizing the deployment


Finally you should check every connector and configuration for entries that point to the old servers. You should delete these entries as to get rid of them totally.


After a successful integration of the second DAG member, you should define a time window when you check if high availability is working properly, this means the following tasks should then be checked:



  1. Active Directory Replication took place properly.
  2. One database goes to shutdown state è this should result in switching over to the passive Database node copy.
  3. The database goes online again è this should result in do not creating a fall back solution, because this is by-design.




As you have seen in the first and second part of this drill down article, the migration from Exchange 2007 SP1 CCR is possible using the existing hardware. The only thing that needs to be discussed is the time when not having high availability. To make sure to provide high availability as soon as possible, you should make sure that this migration step should be carried out as quickly as possible, best over a long weekend or something else.


If you need any further information regarding the steps described above or run into errors, do not hesitate to contact me.



If you would like to read the first part of this article series please go to How to migrate from Exchange 2007 CCR to Exchange 2010 DAG on existing hardware (Part 1).

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