Restoring a Database Availability Group database backup

You can restore a replicated database copy in a Database Availability Group (DAG).

1. Make the database that you want to restore active (Move-ActiveMailboxDatabase).
2. Suspend replication of all passive copies of the database (Suspend-MailboxDatabaseCopy).
3. Unmount the active mailbox database (Dismount-Database).
4. If you are using VSS instant restore, and the During Instant Restore, automatically stop and restart necessary Microsoft Exchange services option is not selected in Microsoft Management Console (MMC), or the STOPSERVICESONIR parameter is set to NO at the command line, stop the following replication services on all copies of the database.
   • (DAG environments only) Exchange Replication Service
   • (Exchange Server 2013 or later only) Exchange Search Host Controller Service
5. Restore the database and logs by using the command line or MMC.
   Restriction: The database must not be mounted automatically after the restore. If you use MMC, ensure that the Mount Databases After Restore option is set to No in the Restore pane. If you use the command line, set the /mountdatabases parameter to NO.

   However, if the During Instant Restore, automatically stop and restart necessary Microsoft Exchange services option is selected, or the STOPSERVICESONIR parameter is set to YES, you can set the Mount Databases After Restore option to YES.

6. If the service is stopped, start the replication service before you mount the active mailbox database. Otherwise, the database mount fails (Mount-Database).
7. Verify the health of the database before you update or reseed to replicated database copies. (Get-MailboxDatabaseCopyStatus)
8. Update or reseed all replicas (Update-MailboxDatabaseCopy). By completing this step, you can help to avoid potential transaction log synchronization problems that might arise if replication is resumed directly.
9. Move the active database to the server that you want (Move-ActiveMailboxDatabase).