Installing Oracle Database 11g R2 on a Linux Server (you can check my previous post) does not provide the database the possibility to preform an automatic startup/shutdown when the system is starts or shutdown, we need to do it manually!
so here is a few steps to make it happen automatically.
The automatic startup and shutdown of the Oracle database can be achieved with the files dbstart and dbshut both provided by Oracle. These files rely on the existence of the file /etc/oratab to work.