Book Image

Oracle Linux Cookbook

By : Erik Benner, Erik B. Thomsen, Jonathan Spindel
Book Image

Oracle Linux Cookbook

By: Erik Benner, Erik B. Thomsen, Jonathan Spindel

Overview of this book

Discover the power of Oracle Linux 8, the free and enterprise-grade Linux distribution designed for use in any environment, with this recipe-style book. Starting with instructions on how to obtain Oracle Linux for both X86 and ARM-based platforms, this book walks you through various installation methods, from running it as a Windows service to installing it on a Raspberry Pi. It unravels advanced topics such as system upgrades using Leapp for major version transitions and using a PXE server and kickstart files for more advanced installations. The book then delves into swapping kernels to take advantage of Oracle’s UEK, exploring boot options, managing software with DNF, and achieving high availability. Detailed recipes involving security topics will assist with tasks such as data encryption, both at rest and in motion. For developers, it offers guidance on building RPM files, using Docker and Podman in a containerized environment, working with AppStreams, and more. For large-scale deployments, the book introduces Oracle Linux Automation Manager for enterprise-level Ansible utilization, from setting up the Ansible server to basic playbook writing. Finally, you’ll discover strategies for cloud migration. By the end of this book, you’ll possess a comprehensive toolkit that will elevate your skills as a Linux administrator.
Table of Contents (16 chapters)

What have they done to YUM, moving to DNF?

YUM was good – it worked and it allowed admins to easily install and patch software. You could even use it to roll back a bad installation. So, what happened to it? Why was DNF released? What is DNF and how hard will it be to learn a new tool?

First, DNF stands for Dandified YUM and is a rewrite of the YUM software. It was released in 2013 in Fedora 18 and was built to address many issues that YUM was starting to face.

The two most common problems with YUM were performance and RAM usage:

  • Poor performance: YUM had performance issues. A lot of this was caused by dependency resolution, the process in which all the packages and their dependencies are put together. This process could take as long as 10 minutes. DNF moved to libsolv, which significantly decreased the time to resolve complex dependencies. This is now more common that ever, with some applications requiring 30+ RPMs.
  • High RAM usage: YUM uses a lot of RAM; this...