Book Image

Red Hat Enterprise Linux 9 Administration - Second Edition

By : Pablo Iranzo Gómez, Pedro Ibáñez Requena, Miguel Pérez Colino, Scott McCarty
2 (2)
Book Image

Red Hat Enterprise Linux 9 Administration - Second Edition

2 (2)
By: Pablo Iranzo Gómez, Pedro Ibáñez Requena, Miguel Pérez Colino, Scott McCarty

Overview of this book

With Red Hat Enterprise Linux 9 becoming the standard for enterprise Linux used from data centers to the cloud, Linux administration skills are in high demand. With this book, you’ll learn how to deploy, access, tweak, and improve enterprise services on any system on any cloud running Red Hat Enterprise Linux 9. Throughout the book, you’ll get to grips with essential tasks such as configuring and maintaining systems, including software installation, updates, and core services. You’ll also understand how to configure the local storage using partitions and logical volumes, as well as assign and deduplicate storage. You’ll learn how to deploy systems while also making them secure and reliable. This book provides a base for users who plan to become full-time Linux system administrators by presenting key command-line concepts and enterprise-level tools, along with essential tools for handling files, directories, command-line environments, and documentation for creating simple shell scripts or running commands. With the help of command line examples and practical tips, you’ll learn by doing and save yourself a lot of time. By the end of the book, you’ll have gained the confidence to manage the filesystem, users, storage, network connectivity, security, and software in RHEL 9 systems on any footprint.
Table of Contents (26 chapters)
1
Part 1 – Systems Administration – Software, User, Network, and Services Management
9
Part 2 – Security with SSH, SELinux, a Firewall, and System Permissions
14
Part 3 – Resource Administration – Storage, Boot Process, Tuning, and Containers
21
Part 4 – Practical Exercises

Setting default mounts and options in fstab

In the previous section, we introduced how disks and partitions can be mounted so that our services and users can make use of them. In this section, we will learn how to make those filesystems available in a persistent way.

The /etc/fstab file contains the filesystem definitions for our system. Of course, it also has a dedicated manual page that can be checked with man fstab. It contains useful information about the formatting, fields, ordering, and more that must be taken into consideration, as this file is critical for the smooth operation of the system.

The file format is defined by several fields separated by tabs or spaces, with lines starting with a # character considered as comments.

For example, we will use this line to look at each field description:

LABEL=/ / xfs defaults 0 0
[.1.] [2] [3] [..4..] [5][6]

The first field is the device definition, which can be a special block device, a remote filesystem, or—as...