The inittab file, located at /etc/inittab, is used to configure the system initialization process on Linux and Unix systems. It determines the default runlevel of the system, as well as the processes that are started or stopped when the system enters or exits a particular runlevel.
To update the inittab file and apply the changes without rebooting the server, you can use the init q command, which reloads the inittab file and re-executes the init process.
Here's an example of how you can use the init q command to update the inittab file and apply the changes:
init q
This command will reload the inittab file and re-execute the init process, without affecting the current runlevel or the processes that are currently running on the system.
Keep in mind that the init q command may not be available on all Linux or Unix systems. On some systems, you may need to use the telinit q command instead.
For more information about the init and telinit commands and their available options, you can consult their man pages or use the init --help and telinit --help commands.
Note: It's important to be careful when modifying the inittab file, as incorrect configurations can prevent the system from booting or functioning properly. It's always a good idea to make a backup copy of the inittab file before making any changes.