Change Static Parameter in RAC Environment

1) Check Parameter is static or dynamic
11:49:35 orcl1 > select name, value, issys_modifiable from v$parameter where name='processes';

NAME                 VALUE                ISSYS_MOD
-------------------- -------------------- ---------
processes            400                  FALSE

1 row selected.

The Value is False.It means the parameter is static.

2) Check Whether database Instance Started with PFILE or SPFILE?
11:49:44 orcl1 > select count(1) from v$spparameter where isspecified = 'TRUE';

COUNT(1)
----------
81

1 row selected.

The view returns NULL values if a PFILE was used to start up the instance.

or,

11:50:26 orcl1 > select name, value from v$parameter where name = 'spfile';

NAME                 VALUE
-------------------- --------------------
spfile               /ora_data/db/apps_st/data/spfileorcl.ora

1 row selected.

or,

11:50:45 orcl1 > show parameter spfile;

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
spfile                               string      /ora_data/db/apps_st/data/spfileorcl.ora

Check the same on node 2 also.If the valus is same it means the instance is running with common spfile.

3) Change the Parameter
ALTER SYSTEM SET processes=500 scope=spfile sid='*';

4) Bounce the Instances