Preface
Linux is everywhere, from personal devices to the largest supercomputers, from the computer labs at universities to Wall Street or the International Space Station, and even Mars! Red Hat Enterprise Linux (RHEL) is the most used Linux distribution in enterprise environments and knowing how to use it is a key skill for anyone in technology. No matter whether you are completely into managing infrastructure or you are a developer interested in knowing more about the platform you want to deploy on, learning about Linux – and, more precisely, about RHEL – will help you be more effective and could even boost your career.
In this book, we cover the basic RHEL administration skills from a very practical perspective, providing examples and tips that we have learned from our experience in “the trenches.” You will be able to follow it from beginning to end, being able to practice with each step while learning about how things are built and why they behave as they do.
We hope you enjoy this book, that you make the most of it, and that you end up, after reading it, with a strong foundation of RHEL administration skills. That’s what we wrote it for.
Enjoy reading...and practicing!
Who this book is for
Anyone that aspires to build and work on IT infrastructures using Linux will benefit from this book as a reference for different useful tasks, tips, and best practices. It will help anyone seeking to pass the Red Hat Certified Systems Administrator (RHCSA) exam, although it will be no substitute for the official training, in which labs and specially crafted tests will be run during the whole process. The scope of the book is adjusted to the RHCSA, extending it with advice from real-world experience and many practical examples.
What this book covers
Chapter 1, Getting RHEL Up and Running, covers the installation of RHEL, from obtaining the software and the subscriptions to the installation of the system itself.
Chapter 2, RHEL 9 Advanced Installation Options, introduces advanced use cases for the installer, including deploying instances in the cloud and automating the installation.
Chapter 3, Basic Commands and Simple Shell Scripts, explains the daily commands that will be used during system administration, and how can they be automated via shell scripting.
Chapter 4, Tools for Regular Operations, shows the simple tools that are available in our system that can be used for regular daily operations, such as starting or enabling a system service or reviewing what is going on in the system through logs.
Chapter 5, Securing Systems with Users, Groups, and Permissions, covers how to manage users, groups, and permissions in any Linux system, with some specifics on RHEL.
Chapter 6, Enabling Network Connectivity, goes through the steps to connect a system to the network and the possible ways it can be configured.
Chapter 7, Adding, Patching, and Managing Software, reviews how the steps to add, remove, and update can be managed in our system, including examples for upgrades and rollbacks.
Chapter 8, Administering Systems Remotely, covers how to remotely connect to your system in order to be more effective. It includes using ssh connections to create keys and using a terminal multiplexer (tmux).
Chapter 9, Securing Network Connectivity with firewalld, instructs you on how the network firewall configuration works in RHEL and how to properly manage it, including managing zones, services, and ports.
Chapter 10, Keeping Your System Hardened with SELinux, covers usage and basic troubleshooting of SELinux.
Chapter 11, System Security Profiles with OpenSCAP, explains how to run security profiles with OpenSCAP and check compliance in RHEL with typical regulations.
Chapter 12, Managing Local Storage and Filesystems, covers filesystem creation, mount points, and general storage management.
Chapter 13, Flexible Storage Management with LVM, explains how Logical Volume Manager (LVM) empowers more flexible storage management by being able to add disks and extend logical volumes.
Chapter 14, Advanced Storage Management with Stratis and VDO, introduces Virtual Data Optimizer (VDO) and how it can be used in our system to deduplicate storage, as well as using Stratis to manage storage more easily.
Chapter 15, Understanding the Boot Process, explains how the system boots and the details that make it important.
Chapter 16, Kernel Tuning and Managing Performance Profiles with tuned, explains how kernel tunning works and how to use tuned for predefined profile usage.
Chapter 17, Managing Containers with Podman, Buildah, and Skopeo, covers containers and tools for managing and building them.
Chapter 18, Practice Exercises – 1, allows you to test your acquired knowledge.
Chapter 19, Practice Exercises – 2, gives more complex testing of your acquired knowledge.
To get the most out of this book
All software requirements will be indicated in the chapters. Note that this book assumes that you have access to a physical or virtual machine, or have access to the internet to create a cloud account in order to perform the operations that the book will guide you through.
|
Software/hardware covered in the book |
Operating system requirements |
|
Red Hat Enterprise Linux 9 |
You will need to install RHEL. It can be installed on a virtual machine on Linux, macOS, or Windows. |
If you are using the digital version of this book, we advise you to type the code yourself or access the code from the book’s GitHub repository (a link is available in the next section). Doing so will help you avoid any potential errors related to the copying and pasting of code.
Download the example code files
You can download the example code files for this book from GitHub at https://github.com/PacktPublishing/Red-Hat-Enterprise-Linux-RHEL-9-Administration. If there’s an update to the code, it will be updated in the GitHub repository.
We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!
Download the color images
We also provide a PDF file that has color images of the screenshots and diagrams used in this book. You can download it here: https://packt.link/NcDqa.
Conventions used
There are a number of text conventions used throughout this book.
Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: “Mount the downloaded RHEL9.iso disk image file as another disk in your system.”
A block of code is set as follows:
#!/bin/bash echo "Hello world"
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
[default] branch = main repo = myrepo username = bender protocol = https
Any command-line input or output is written as follows:
$ mkdir scripts
$ cd scripts
Bold: Indicates a new term, an important word, or words that you see on screen. For instance, words in menus or dialog boxes appear in bold. Here is an example: “Select System info from the Administration panel.”
Tips or Important Notes
Appear like this.
Get in touch
Feedback from our readers is always welcome.
General feedback: If you have questions about any aspect of this book, email us at [email protected] and mention the book title in the subject of your message.
Errata: Although we have taken every care to ensure the accuracy of our content, mistakes do happen. If you have found a mistake in this book, we would be grateful if you would report this to us. Please visit www.packtpub.com/support/errata and fill in the form.
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