You create a database availability group (DAG) that contains two or more member servers in a Microsoft Exchange Server 2010 environment.
You configure the replication service between the member servers of the DAG.
Some users perform a Multi-Mailbox Search function against the DAG.
In this scenario, you may encounter mailbox database replication latency in the DAG.
Note When this issue occurs, if the CheckDatabaseRedundancy.ps1 script is running to monitor the redundancy of replicated mailbox databases, you will receive an event that only a single healthy copy of a replicated database exists.
This issue occurs because the Multi-Mailbox Search function is running during the database replication process. This behavior causes a heavy disk I/O load. Therefore, the latency of replication increases.
To resolve this issue, install the following update rollup:
2645995 Description of Update Rollup 1 for Exchange Server 2010 Service Pack 2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the Multi-Mailbox Search function, visit the following Microsoft website: