Linux Run level
|1||Single User Mode|
|2||Multi User Mode without Network|
|3||Multi User Mode with Network, Text Mode|
|4||Not used, User customize defined|
|5||Multi User Mode with GUI|
Each Run level processes are list under /etc/rc.d
rc is the script which would call the correspond run level script. For example, in the run level 0 ( shutdown), rc script would run stop process inside the rc0.d directory.
If we look into rc3.d directory, it is actually symbolic link to the /etc/init.d
Therefore, if we want to have our oracle process auto start/shutdown in the correspond run level, we need to add/update the script there.
Update oracle script within init.d directory
dbstart or dbshut would read the oratab for startup or shutdown all the db list in the oratab file.
However, for the instance, we have to add it.
Update oratab ( /etc/oratab)
Add the new database entry in the list.
Run level ( rcX.d) script –> init.d script –> oracle related scripts ( dbstart, dbshut ) –> read the oratab for database list.