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 RPM internals

Linux distributions tend to have their own package manager, from Debian with .deb to Pacman in Arch Linux and other more exotic mechanisms. The intention of package managers is to keep software installed on the system, update it, patch it, keep dependencies, and maintain an internal database of what is installed on the system. RPM is used by distributions such as Fedora, openSUSE, CentOS, Oracle Linux, and, of course, RHEL.

To handle RPMs, the rpm command is available on the system, however, since the introduction of yum/dnf, it is hardly ever used in system administration, and is not included in RHCSA.

RPMs contain the following:

  • The files to be installed on the system, stored in CPIO format and compressed
  • Information on permissions and the assigned owner and group for each file
  • The dependencies required and provided by each package, along with, conflicts with other packages
  • Install, uninstall, and upgrade scripts to be applied...