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

Testing a VDO volume and reviewing the stats

In order to test deduplication and compression, we will test with a big file, such as the RHEL 9 KVM guest image or the installation ISO available at https://access.redhat.com/downloads/content/479/ver=/rhel---9/9.0/x86_64/product-software.

Once downloaded, save it as rhel-9.0-x86_64.iso and copy it four times to our VDO volume:

cp rhel-9.0-x86_64.iso /mnt/vm1.iso
cp rhel-9.0-x86_64.iso /mnt/vm2.iso
cp rhel-9.0-x86_64.iso /mnt/vm3.iso
cp rhel-9.0-x86_64.iso /mnt/vm4.iso

This would be the typical case for a server holding VMs that start with the same base disk image, but do we see any improvement?

Let’s execute vdostats --si to verify the data. Note that the image downloaded is 8.5 GB, as reported by ls –si. The output obtained from vdostats --human-readable is as follows:

 Device                Size     &...