I had come across an issue in database replication on one of the database of my DAG yesterday. The ‘Copy Status’ where shown as ‘Failed and Suspended’ as below:

I have tried to ‘Activate Database Copy’, but that has failed. Then I have gone through some web research and found a Microsoft article here: http://technet.microsoft.com/en-us/library/ff359982(v=exchg.140).aspx

When following the procedures I was able to resolve the issue successfully.

Hope the following steps will help you out if you are facing such an issue:

1. Open Windows Powershell and run the cmdlet: Get-MailboxDatabaseCopyStatus -Identity <databaseName>.  Substitute <databaseName> with the name of the failed database. You can see one of the databse included in the DAG is failed as  ‘Failed and Suspended’ shown below: Also note that Copy queue length can be seen as a bigger number. Idealy, that should be zero in a healthy condition.

2. Suspend replication to the database by running the cmdlet: Suspend-MailboxDatabaseCopy <databaseName>\<ReplicaServerName> .You will be asked a confirmation Y/N/All. Tpe Y and confirm as below:

3. Reseed the database copy by running Update-MailboxDatabaseCopy <databaseName>\<ReplicaServerName> -SourceServer <ActiveServerName> -DeleteExistingFiles:$True . Substitute SourceServer with an Active copy in the DAG. You will be asked a confirmation Y/N/All. Tpe Y and confirm as below:

This operation has took a long time depends up on how big is the Copy queue length. You can see the progress indicator as:

See EMC now and ensure that the database status is now shown as ‘Resynchronizing’

After the reseeding is complete, you can see that the ‘Copy Queue Length’ is zero.

4. Resume replication by running the cmdlet Resume-MailboxDatabaseCopy <databaseName\<ReplicaServerName>

The above steps will help you out to fix the DAG replication of a database from it’s failed state.