PROBLEM:

While trying to recreating a controlfile in RAC database, got below error.

ERROR at line 1:
ORA-01503: CREATE CONTROLFILE failed
ORA-12720: operation requires database is in EXCLUSIVE mode

SOLUTION:

Before recreating controlfile in RAC database, we need to set the cluster_database parameter to FALSE.

SQL> show parameter cluster_database

NAME                                 TYPE        VALUE
------------------------------------ ----------- -----------------------
cluster_database                     boolean     TRUE
cluster_database_instances           integer     2


alter system set cluster_database='FALSE' scope=spfile sid='*';

SQL> show parameter cluster_database

NAME                                 TYPE        VALUE
------------------------------------ ----------- -----------------------
cluster_database                     boolean     FALSE
cluster_database_instances           integer     2

Now try to recreate the control file again. It will succeed.

The Same error occurs when you try to duplicate a database from RAC TO RAC.