Enable Archive Log Mode in Oracle RAC 10g Database

The following will be the steps:
1- Login to one of the clustered database nodes and change parameter cluster_database to false:
   sqlplus "/ as sysdba"
   alter system set cluster_database=false scope=spfile sid='racdb1'
  
2- Stop all database instances:
    srvctl stop database -d racdb

3- On any node startup one instance in mount state and enable archivelog mode:

   sqlplus "/ as sysdba"
   startup mount;
   alter database archivelog;


4- Shutdown the previous running node:
   sqlplus "/ as sysdba"
   shutdown immediate;

5- Start all instance back:

     srvctl start database -d racdb

To check the mode:

   sqlplus "/ as sysdba"
   archive log list;

or

 select log_mode from v$database;