Disabling Archivelog mode in oracle database

if it is active follow this step 

SQL> shutdown immediate

SQL> startup mount

SQL> alter database noarchivelog;

SQL> alter database open;

For further description : 

What is the "default" way to disable archive log mode in a database where archive log mode is currently active?

Is the easiest way to disable archive log mode to shutdown the database and afterwards disable archive log mode and than startup the database again ?

Answer:The method for disabling archive log mode described above is the only way to disable archive log mode.

Shutdown edit pfile / spfile (spfile when instance is up of course) to say log_archive_start = false.startup mount

alter database noarchivelog;

alter database open;Remember that once you disable archive log mode you need to take a fresh backup once archive log mode is turned back on.

The Oracle documentation says the following about enabling and disabling archive logging in RAC environments:

"To enable archive logging in RAC environments, the database must be mounted but not open. Then start RAC in a disabled state. To do this:

 Disabling Archive log mode:

1. Shut down all instances.

2. Reset the CLUSTER_DATABASE parameter to false on one instance. If you are using the server
parameter file, make a sid-specific entry for this.

3. Add settings for the LOG_ARCHIVE_DEST_n, LOG_ARCHIVE_FORMAT, and LOG_ARCHIVE_START parameters to the parameter file. You can multiplex the destination to up to ten locations, and the LOG_ARCHIVE_FORMAT parameter should contain the %t parameter to include the thread number in the archived log file name.

4. Start up the instance on which you have set CLUSTER_DATABASE to false.

5. Enter the following statement:
   ALTER DATABASE ARCHIVELOG

6. Shut down the instance.

7. Change the value of the CLUSTER_DATABASE parameter to true.

8. Restart your instances.

These steps should allow you to disable archive log mode.

To disable archive logging, follow the same steps but use the NOARCHIVELOG clause of the ALTER DATABASE statement."