RHEL Linux - Red Hat System Administration Practice Exam

Which file provides system configuration information during boot-up?

1. /etc/fstab

2. /etc/sysctl.conf

3. /etc/inittab

4. /etc/hosts

The correct answer is: /etc/inittab

The file that provides system configuration information during boot-up is /etc/inittab. This file is essential for managing the different run levels of the system in traditional System V-style initialization. It defines the default runlevel, the processes that should be started or stopped at each runlevel, and various configuration aspects of the system's initialization process. Understanding the role of /etc/inittab is important because it directly affects which services and daemons are initiated when the system starts up. Although modern systems might use alternatives like systemd with unit files, /etc/inittab was historically significant in defining the behavior of the system at boot time. In contrast, the other files have different purposes. /etc/fstab, for instance, is primarily used for defining how disk partitions and devices are mounted at boot time, but it does not directly configure services or run levels. /etc/sysctl.conf is used for modifying kernel parameters at runtime and does not dictate boot processes. Finally, /etc/hosts serves as a local hostname resolution file, which assists in mapping hostnames to IP addresses but is not involved in the boot configuration of services or run levels.