Forcefully Reseeding an Exchange Server on Exchange 2010

One of our customers had an Exchange 2010 DAG with databases on two servers.  One of the databases could not be mounted.  Before calling us, the customer removed one of the servers as a database copy.  So we only had one server with one copy of the Mailbox Database.

We attempted to re-add the other server as a DAG Member after the customer removed it with the following command:

Add-MailboxDatabaseCopy -Identity "MAILBOXDATABASE" -MailboxServer "EXHANGESERVER"

The DB was created, however the seed fails.  This can be caused by real-time anti-virus on Exchange servers without the appropriate exclusions in place or a corrupt transaction log / or inconsistent transaction log checkpoint file.

To fix this we forced the seed using the following procedure:

1. We dismounted the active database.
2. We suspended the passive copy (if active)
3. We deleted the EDB and Log Files from the Passive Server.  (You can move these to a different location as an alternative).
4. We checked the Active Server was in a clean shutdown state - see https://clintboessen.blogspot.com/2010/09/flush-transaction-logs-in-exchange.html
5. Once we know the Active Server database was in a clean shutdown, we cleared all transaction logs only from the production server by moving the logs to a temp folder.
6. We then re-mounted the Active Server database.  This database needed a force mount (Mount-Database DatabaseName -Force)
7. Lastly we forcefully updated the passive server with the following command:

Update-MailboxDatabaseCopy -Identity "MAILBOXDATABASE\EXCHANGESERVER" -DeleteExistingFiles

The PowerShell window will show a progress bar of the reseed progress.

Hope this post has been helpful.