If you have installed SP3 for Microsoft Exchange 2010 you can experience an issue with database copy status.
When activating a passive copy of an Exchange 2010 SP3 database via PowerShell or the Exchange Management Console, the mounted database will dismount without issue and the passive copy will mount. While at the initializing stage on the now passive copy, the database copy status will change to a failed state.
The status message for the database copy shows failed, and the log indicates:
“The Microsoft Exchange Replication service encountered an error while inspecting the logs and database for DB\Server on startup. Error: File check failed : Logfile ‘f:\logs\DB\Enn.log’ is generation 2024; however the expected generation is 2004.”