I have a two node RAC database and i want to do a active clone using RMAN duplicate command on the same server. I am using the same db_name and a different db_unique name for the new clone database.In the RMAN duplicate command i need to provide the db_unique_name or database SID , Database SID using which i did nomount.
When doing a DUPLICATE TO ... the name of the new database must be different. So the DB_NAME of the new database you are creating must be different from the existing one.
Since you are doing a DUPLICATE on the same host, you must be careful to use db_file_name_convert (if not using OMF) or SET NEWNAME to define new names for datafiles of the new database instead of overwriting the existing database !!!