alter database backup controlfile to trace as ‘/home/oracle/controlfile.ora’;

Below are two sets of SQL statements, each of which creates a new
– control file and uses it to open the database. The first set opens
– the database with the NORESETLOGS option and should be used only if
– the current versions of all online logs are available. The second
– set opens the database with the RESETLOGS option and should be used
– if online logs are unavailable.
– The appropriate set of statements can be copied from the trace into
– a script file, edited as necessary, and executed when there is a
– need to re-create the control file.