ORA-12720: operation requires database is in EXCLUSIVE mode

jfgdf

PROBLEM
When I try to create an controlfile for a RAC database using the CONTROLFILE Trace. I was throw with the below error message
SQL> @c.sql
CREATE CONTROLFILE REUSE DATABASE "XE1" RESETLOGS FORCE LOGGING ARCHIVELOG
*
ERROR at line 1:
ORA-01503: CREATE CONTROLFILE failed
ORA-12720: operation requires database is in EXCLUSIVE mode
SOLUTION
After analyzing the issue, I found that cluster_database parameter needs to be set as FALSE. So I am proceeding with the change.
SQL> alter system set cluster_database=FALSE scope=spfile sid='*';
System altered.
SQL> shutdown abort;
ORACLE instance shut down.
SQL>
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options
STARTING THE DATABASE
$sqlplus / as sysdba
SQL*Plus: Release 11.2.0.2.0 Production on Fri Nov 11 14:30:58 2011
Copyright (c) 1982, 2010, Oracle.  All rights reserved.
Connected to an idle instance.
SQL> startup nomount
ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance
ORACLE instance started.
Total System Global Area 1.4431E+10 bytes
Fixed Size                  2240272 bytes
Variable Size            3892314352 bytes
Database Buffers         1.0503E+10 bytes
Redo Buffers               34148352 bytes
SQL> @c.sql
Control file created.
Once the controlfile created and open the database, I have change the parameter to TRUE
SQL> alter system set cluster_database=TRUE scope=spfile sid='*';
Once you issue the command, you need to bounce the DB.