Enabling Archive Log mode in Oracle

1. Login as sysdba

2. Configure the archive dest.

     db_recovery_file_dest

     db_recovery_file_dest_size

3. Shutdown instance.

4. Start the instance in mount mode.

    startup mount; 

5. Alter database archivelog;

6. Opent the database.

    alter database open;

7. Check archivelog status

     archive log list;