Today I encountered a problem where a server gave an error stating that a certain MMS database was not found. This was strange since no service and known functionality was using this particular database. So after some searching and troubleshooting I found out that it was an old DB that is not used anymore and it still has a reference in SharePoint. There is some task or job that goes through the MMS databases every two hours, well on my server at least. So what to do?
See if the database in your error message gets listed with PowerShell:
Get-SPDatabase | Format-Wide
Get-SPDatabase | Format-List
If it is listed here then you can remove it(though be careful and make sure that it is not really used anywhere).
Get-SPContentDatabase 12345678-90ab-cdef-1234-567890abcdef | Remove-SPContentDatabase
Just replace the GUID above with the one with the problem database in your environment.
The error message in Windows Event Logs is something like this:
SQL Database ” on SQL Server instance ” not found. Additional error information from SQL Server is included below.
Cannot open database “” requested by the login. The login failed.
Login failed for user ”.
PS. If you have trouble with getting the proper information with the Get-SPDatabase: http://technet.microsoft.com/en-us/library/dd347677.aspx