This alert indicates that a replication issue affects the mailbox database copies in a particular Microsoft Exchange Server 2010 database availability group (DAG).

Exchange 2010 uses continuous replication to create and maintain database copies. To maintain a synchronized copy of a mailbox database, transaction log files from the active mailbox server are replayed into the passive database of another server in the DAG. This provides high availability and resiliency in the Exchange environment.

The information store is responsible for replaying the log file for the passive copy of the database that is hosted on a server. When a replica instance of a copied database is started, the Replay service contacts the information store and creates an ESE instance for the database to be mounted. This mount is for log replay only. The Replay service Log Replayer component then contacts the store over the RPC STORE ADMIN Interface (ExRpcAdmin.LogReplayRequest) to pass the log files that have to be replayed by the store.

The replication service monitors the replication health of each mailbox database copy. The replication service can restore replication health if it is required. The service must be aware of the current status of each database to make the best database copy available for use. If replication fails, the replication service either takes corrective action, if possible, or reports the problem for administrative attention.

The mailbox database copy is in a Failed state when both of the following conditions are true:

• The database copy cannot copy or replay transaction log files.
  
  
• The database copy is not suspended.
  
  

The replication service periodically examines the failed database copy to determine whether the underlying issue is resolved and whether the database can now copy and replay log files. When the issue is resolved, and if no other issues exist to prevent the database from becoming up-to-date, the copy status is automatically changed to Healthy.

You can use the Get-MailboxDatabaseCopyStatus cmdlet to determine the current replication status for a database. This cmdlet can return information about all copies of a particular database, information about a specific copy of a database on a particular server, or information about all database copies on a server.

To resolve this error, do one or more of the following:

• Review the Application log and System log on your Exchange 2010 servers for related events. For example, events that occur immediately before and after this event may provide more information about the root cause of this error.
  
  
• Review Operations Manager for detailed information about the cause of this problem. For more information, see the "Introduction" section in this article.
  
  
• Check the following performance counter by using Windows Reliability and Performance Monitor:
  
  
  • Object: MSExchange Replication
    
    
• Examine the current replication status for each replica database. To do this, use the Get-MailboxDatabaseCopyStatus cmdlet. To determine the replication status of a particular database copy, run the following command, as appropriate for the particular database:
  
  

  	Copy Code
  Get-MailboxDatabaseCopyStatus -Identity <databaseName>

• If the database has been offline for an extended period, you may have to reseed it. To do this, follow these steps:
  
  
  1. Suspend replication to the database if it is not already suspended. To do this, run the following command:
     
     

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     Suspend-MailboxDatabaseCopy <databaseName>\<ReplicaServerName>

  2. Reseed the database copy. To do this, run the following command:
     
     

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     Update-MailboxDatabaseCopy <databaseName>\<ReplicaServerName> -SourceServer <ActiveServerName> -DeleteExistingFiles:$True

  3. Resume replication. To do this, run the following command:
     
     

     	Copy Code
     Resume-MailboxDatabaseCopy <databaseName\<ReplicaServerName>

For more information, see the following topics in Exchange 2010 Help:

• Understanding Mailbox Database Copies
  
  
• Understanding Database Availability Groups
  
  

If you are not already doing so, consider running the Exchange tools created to help you analyze and troubleshoot your Exchange environment. These tools can help make sure that your configuration aligns with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. To run these tools, go to the Toolbox node of the Exchange Management Console. To learn more about these tools, see Managing Tools in the Toolbox.