I was able to add standby database on RHEL 6.1 using same method.
I used the following link to install ORACLE on RHEL 7.0. Does it have anything to do with oracle group gid is different than RHEL 6.1? On RHEL 7.0, I used oinstall(54321) dba(54322) oper(54323) for gids. On RHEL 6.1, I used oinstall(501) dba(502) oper(503). If it doesnt matter, what should i do?