SQL Database ‘SharePoint_Config’ on SQL Server instance ‘GDFS’ not found. Additional error information from SQL Server is included below.

Cannot open database “SharePoint_Config” requested by the login. The login failed. Login failed for user ‘GOLTENSDXB\SP_Farm’.

Before you go about making any drastic changes to the database; it would be wise to check the Status of the Sharepoint_Config database within the SQL Server Management Studio

Is your Sharepoint_Config Database set to Single User Login?

If yes, we require the trace and kill the session that is connected to this database before we enable multi user

Step 1 – Trace the Session ID connected to the Sharepoint_Config Database

select * from master.sys.sysprocesses 
msp,master.sys.sysdatabases msd 
where msp.spid>50
and msd.name='SharePoint_Config'
and msp.dbid=msd.dbid

Step 2 – Kill the Session and set the Sharepoint_Config Database database to offline mode

kill <spid> [eg: kill 62]
alter database Sharepoint_Config set offline with rollback immediate;

Step 3 – Switch back the Database to Online Mode and set it for Multi-User login

alter database Sharepoint_Config set online,multi_user with rollback immediate;

If your Sharepoint_Config database was not in Single User Login Mode and are still faced with this error; I would recommend below post

http://answers.flyppdevportal.com/categories/sharepoint2010/sharepoint2010setup.aspx?ID=b7ba6c51-3248-4dc2-a476-49cdd4267210