Couldn’t mount the database that you specified. Specified database: mailbox-database1; Error code: An Active Manager operation failed. Error: The database action failed. Error: Operation failed with message: MapiExceptionNotFound: Unable to mount database. (hr=0x8004010f, ec=-2147221233)
http://support.microsoft.com/kb/977960
CAUSE
This issue occurs when the value of the ConfigurationDomainController parameter and the value of the PreferredGlobalCatalogparameter are different. In this scenario, the Mailbox database operation fails because of the replication latency that occurs between the configured domain controllers and the preferred global catalog.
RESOLUTION
To resolve this issue, set the preferred Active Directory server in Exchange Management Shell to the following cmdlet:
Set-ADServerSettings –PreferredServer <DC FQDN>