We want to create a user to monitor ASM disk group.
When you are logged in to an Oracle ASM instance as SYSASM, you can use the combination of CREATEUSER and GRANT SQL statements to create a user who has the SYSASM privilege.
You also can revoke the SYSASM privilege from a user using the REVOKE command, and you can drop a user from the password file using the DROPUSER command.
REM create a new user, then grant the SYSASM privilege
SQL> CREATE USER new_user IDENTIFIED by new_user_passwd;
SQL> GRANT SYSASM TO new_user;
REM connect the user to the ASM instance
SQL> CONNECT new_user AS SYSASM;
REM revoke the SYSASM privilege, then drop the user
SQL> REVOKE SYSASM FROM new_user;
SQL> DROP USER new_user;
These commands update the password file for the local Oracle ASM instance only.
Oracle ASM does not support the creation of external and global users.