While scheduling backup job  through OEM, I've encountered "ora-20446 the owner of the job is not registered". as workaround from metalink simply execute the following command using sysman user:


sqlplus sysman SQL*Plus: Release 11.2.0.1.0 Production on Thu Nov 13 12:14:41 2014 Copyright (c) 1982, 2009, Oracle. All rights reserved. Enter password: Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP, Data Mining and Real Application Testing options SYSMAN@ feco1>execute MGMT_USER_MAKE_EM_USER('DB_USER');


while DB_USER is the user that you use to connect to OEM.



Reference:
Doc ID 463874.1

Change SYS password

It's being long time writing a post in my blog ..

I've inherited newly installed RAC four nodes without OEM configuration and without SYS password which required to configure OEM.

Generally this post for how to change the sys password in RAC environment which seems very simple at the first instance but it has a trick. The trick is when you change the sys password in one instance, it doesn't reflect on other instances unlike any other user so you need to change it in all instances as follows:

SYS@ feco1> alter user sys identified by newPwd;

User altered.

Then login to node2 and do the same

SYS@ feco2> alter user sys identified by newPwd;

User altered.

and do so in all your RAC nodes.

the other solution which is the only one for 10g is to change the password in one instance and then copy your password file (orapw<instance_name>) located in '$ORACLE_HOME/dbs' to other nodes and amend the name accordingly,