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

Understanding the boot process – BIOS and UEFI booting

Computers have hardware-embedded software controllers, also called firmware, that let you manage the very lowest layers of the hardware. This firmware performs the first recognition of what hardware is available in the system and what hardware features are enabled (such as pre-boot network execution, also called PXE).

In the architecture known as PC (short for Personal Computer), also referred to as x86, which Intel and IBM popularized, the embedded firmware is referred to as Basic Input and Output System (BIOS).

The BIOS boot process, with Linux, takes the following steps:

  1. The machine is powered on, and the BIOS firmware is loaded.
  2. The firmware initializes devices such as the keyboard, mouse, storage, and other peripherals.
  3. The firmware reads the configuration, including the boot order, specifying which storage device is the one to continue the boot process with.
  4. Once the storage device has been...