Table Of ContentRed Hat Enterprise Linux 9
Administration
A comprehensive Linux system administration guide
for RHCSA certification exam candidates
Pablo Iranzo Gómez
Pedro Ibáñez Requena
Miguel Pérez Colino
Scott McCarty
BIRMINGHAM—MUMBAI
Red Hat Enterprise Linux 9 Administration
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To all the people contributing to and being part of open source, building it one piece at a time,
and pushing its boundaries to make huge things possible.
– Pablo Iranzo Gómez
To the ones that once crossed my path and made a difference.
– Pedro Ibáñez Requena
Contributors
About the authors
Pablo Iranzo Gómez is a software engineer who started his Linux exposure while studying physics.
He was also involved in LUGs and some projects related to HPC clusters and system administration
and consultancy.
Currently, he is a principal software engineer at Red Hat’s TelCo 5G OpenShift management integration
department, leveraging his experience in consulting, cloud technical account management, and OpenStack
software maintenance in industries such as hotel, retail, airlines, government, Telco, 5G, Partner, and
IT – covering system administration and automation, virtualization, PaaS, support, the cloud, and so
on. He has a broad understanding of different views, needs, and risks across the industry.
Pablo was born in and lives in Valencia, Spain, with his family.
I want to thank my wife, Eva and my sons, Pau and Roi, for the support provided while working on
this project, Javier for the moral support provided during this writing, and Miquel for always being
there. Not forgetting about Miguel, who gave me this opportunity and helped get the prior version
ready, and, of course, the whole Packt team that has been helping, guiding, and advising during the
whole process.
Pedro Ibáñez Requena is a software engineer who started his Linux adventure playing with Linux
distributions provided on CDs by magazines. He was also involved in LUGs while studying software
engineering at Universitat de València.
Currently, he is a principal systems engineer in Red Hat’s Telco 5G field engineering team, focusing on
OpenShift, with experience in automation, security, high availability, and databases. His experience
was built in industries such as retail, finance, insurance, and Telco. He has been involved in the design,
configuration, and deployment of complex IT systems including data storage, networking, monitoring,
and PaaS and SaaS systems where he has a broad understanding of different views, needs, and risks
across the industry.
Pedro was born in Alcoy and lives in Valencia, Spain, with his family.
I want to thank my girls, Katja and Maya, for the endless days at home, playing, chatting, swimming,
traveling, or discussing because, without them, I wouldn’t be who I am today. To my parents, for
supporting me to study what I wanted and for providing when I needed it. To Carles and Alex, because
their help in this race was life-changing. To Pablo, who thought about me helping him with this book,
and lastly, to all the people that make my day, the Telco 5G field engineering team, and the Packt team
that made this possible.
Miguel Pérez Colino is an experienced technology enthusiast with a clear orientation toward IT,
free/open source software, and open standards. His career has grown in the IT field with connections
in every direction. From user support and teaching; through systems and network administration; to
systems engineering, systems architecture, IT strategy definition, and now, as a senior manager for
the Tanzu portfolio to bring Kubernetes closer to customers. He loves designing solutions and tools,
making them useful and easy to use.
Scott McCarty is a principal product manager at Red Hat for the container subsystem team, which
enables key product capabilities in OpenShift Container Platform and Red Hat Enterprise Linux. His
focus areas include container runtimes, tools, and images. Scott is a social media start-up veteran, an
e-commerce old-timer, and a weathered government research technologist, with experience across
a variety of companies and organizations, from 7-person start-ups to 15,000-employee technology
companies. This has culminated in a unique perspective on open source software development, delivery,
and maintenance.
About the reviewers
Derek Thurston is a senior solutions architect at Red Hat and has been working with open source
software since the mid-1990s. After graduating from a small merchant marine college in coastal Maine,
Derek landed a job in the “IT department” at a naval architecture firm in Arlington, VA, where he
started using Linux. Derek has worked with SGI and HP/UX systems and did his part to help save
the world by converting COBOL programs to four-digit years in the late 1990s. Having worked with
a variety of public and private sector entities, he has spent over 25 years helping customers find the
right open source tools and technologies.
I would like to thank my wife, who inspires me every day, my son, who is always down for a cool
adventure, and my two dogs, who are my steadfast officemates.
Luis Sampaio is a system engineer. He has managed servers since 2010. He has experience with Red
Hat, Ubuntu, and Debian. He has some certifications such as RHCE and RHCSA.
Luis has diverse experiences in different private, hybrid cloud architectures with Amazon Web Services
and Azure, as well as experience with DevOps tools such as Ansible and containers.
He likes to share his tech views and experiments with a community. Luis loves playing poker with
friends and visiting new cities.
I would like to thank my family (my mother, Silvia, for all the support, my wonderful wife, Yolanda,
and my terrific and smart son, Bruno Miguel) for unlimited patience and tolerance.
My wife is my best friend, and I love her dearly. Without her love and the support from her, I would
never have been able to finish the book.
Table of Contents
Preface xvii
Part 1 – Systems Administration – Software, User,
Network, and Services Management
1
Getting RHEL Up and Running 3
Technical requirements 3 Preparation for a physical server installation 7
Obtaining RHEL and a subscription 4 Preparation for a virtual server installation 10
Running an RHEL installation 14
Installing RHEL 9 7
Summary 39
2
RHEL 9 Advanced Installation Options 41
Technical requirements 41 Deploying RHEL on the cloud 47
Automating RHEL deployments with Installation best practices 56
Anaconda 42 Summary 58
3
Basic Commands and Simple Shell Scripts 59
Logging in as a user and managing Using and understanding the command prompt 62
multi-user environments 60
Changing users with the su command 62
Using the root account 61
