Procedure on how to decommission Exchange Server 2010 with DAG configured after migrating to Exchange Server 2013

Question

Hi,

Good Day!

May I ask what is the proper way of decommissioning of Exchange Server 2010 with DAG configured after migrating to Exchange Server 2013.

Thanks,
Raymond

Answer 1

1. Ensure all mailboxes are moved to 2013 including the arbitration mailboxes
   Get-Mailbox -Arbitration | New-MoveRequest -TargetDatabase <2013DB>
2. Remove all database copies from all the servers except the last one
   https://learn.microsoft.com/en-us/exchange/high-availability/manage-ha/remove-db-copies?view=exchserver-2019
3. Remove all the mailbox severs from the DAG:
   https://learn.microsoft.com/en-us/exchange/high-availability/manage-ha/dag-memberships?view=exchserver-2019#use-the-eac-to-manage-database-availability-group-membership
4. Uninstall Exchange from each 2010 server ( setup will alert if you not removed 2010 as a source server in any send connector or still have a mailbox on the server)
   Add/Remove Programs and uninstall.

Answer 2

Hi Raymond,

Agree with Andy, if you have finished the migration to Exchange 2013 (moved all the mailboxes including arbitration mailboxes, configured DNS records to point to Exchange 2013),
to decommission the DAG, you may need to first remove the database copies,then remove the nodes from the DAG and finally remove the DAG.

In addition, I would recommend to shut down the Exchange 2010 servers for a few days before finally decommissioning them to check if there are any problems with the mail flow or client access.

There is also an article from Exchange Team Blog for your reference: Best practices when decommissioning Exchange 2010

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Answer 3

Hi Andy and Kael,

Good Day!

Sorry for the late response and thank you for sharing your thoughts.

I confused in some articles that I have reading because they will remove the databases in each server after removing the database copy and DAG.

May we ask if do I need to remove the Offline Address Book? If yes, when I will this procedure?

Thanks,
Raymond

Answer 4

Hi Kael,

Good Day!

Meaning I need to remove the OAB of 2010 since the Exchange Server 2013 is already added before removing the DAG configuration?

Thanks,
Raymond

Answer 5

Hi Kael,

Good Day!

This is noted. I will run that command to check the OAB and will update you once we have schedule with the client to do this.

May I ask if the OAB is required to remove when decommissioning of Exchange Server 2010 after the upgrade to Exchange Server 2013?

Thanks,
Raymond