RHCSA Red Hat Enterprise Linux 9 Certification Study Guide EX200 (2023)
Prepare for success with RHCSA Red Hat Enterprise Linux 9 Certification Study Guide EX200 (2023), a comprehensive guide to your certification test.
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RHCSA®
Red Hat® Enterprise Linux® 9
Certification Study Guide
(Exam EX200)
Red Hat® Enterprise Linux® 9
Certification Study Guide
(Exam EX200)
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McGraw Hill is an independent entity from Red Hat®, Inc. and is not affiliated with Red
Hat, Inc. in any manner. This study/training guide and/or material is not sponsored
by, endorsed by, or affiliated with Red Hat, Inc. in any manner. This publication and
accompanying media may be used in assisting students to prepare for a Red Hat
RHCSA certification exam. Neither Red Hat nor McGraw Hill warrant that use of this
publication and accompanying media will ensure passing any exam. Red Hat®, Red Hat
Enterprise Linux®, RHCE®, RHCSA®, and the Red Hat logo and Red Hat “Shadowman”
logo are trademarks or registered trademarks of Red Hat, Inc. in the United States and
certain other countries. All other trademarks are trademarks of their respective owners.
Michael Jang
Alessandro Orsaria
New York Chicago San Francisco
Athens London Madrid Mexico City
Milan New Delhi Singapore Sydney Toronto
RHCSA®
Red Hat® Enterprise Linux® 9
Certification Study Guide,
Eighth Edition (Exam EX200)
Hat, Inc. in any manner. This study/training guide and/or material is not sponsored
by, endorsed by, or affiliated with Red Hat, Inc. in any manner. This publication and
accompanying media may be used in assisting students to prepare for a Red Hat
RHCSA certification exam. Neither Red Hat nor McGraw Hill warrant that use of this
publication and accompanying media will ensure passing any exam. Red Hat®, Red Hat
Enterprise Linux®, RHCE®, RHCSA®, and the Red Hat logo and Red Hat “Shadowman”
logo are trademarks or registered trademarks of Red Hat, Inc. in the United States and
certain other countries. All other trademarks are trademarks of their respective owners.
Michael Jang
Alessandro Orsaria
New York Chicago San Francisco
Athens London Madrid Mexico City
Milan New Delhi Singapore Sydney Toronto
RHCSA®
Red Hat® Enterprise Linux® 9
Certification Study Guide,
Eighth Edition (Exam EX200)
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ISBN: 978-1-26-046208-1
MHID: 1-26-046208-0
The material in this eBook also appears in the print version of this title: ISBN: 978-1-26-046207-4, MHID: 1-26-046207-2.
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McGraw Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet your requirements
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for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom. McGraw Hill has
no responsibility for the content of any information accessed through the work. Under no circumstances shall McGraw Hill and/
or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of
or inability to use the work, even if any of them has been advised of the possibility of such damages. This limitation of liability
shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tort or otherwise.
publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without
the prior written permission of publisher, with the exception that the program listings may be entered, stored, and executed in a
computer system, but they may not be reproduced for publication.
ISBN: 978-1-26-046208-1
MHID: 1-26-046208-0
The material in this eBook also appears in the print version of this title: ISBN: 978-1-26-046207-4, MHID: 1-26-046207-2.
eBook conversion by codeMantra
Version 1.0
All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trade-
marked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringe-
ment of the trademark. Where such designations appear in this book, they have been printed with initial caps.
McGraw Hill eBooks are available at special quantity discounts to use as premiums and sales promotions or for use in corporate
training programs. To contact a representative, please visit the Contact Us page at www.mhprofessional.com.
Information has been obtained by McGraw Hill from sources believed to be reliable. However, because of the possibility of hu-
man or mechanical error by our sources, McGraw Hill, or others, McGraw Hill does not guarantee the accuracy, adequacy, or
completeness of any information and is not responsible for any errors or omissions or the results obtained from the use of such
information.
TERMS OF USE
This is a copyrighted work and McGraw Hill (“McGraw Hill”) and its licensors reserve all rights in and to the work. Use of this
work is subject to these terms. Except as permitted under the Copyright Act of 1976 and the right to store and retrieve one copy
of the work, you may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon,
transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it without McGraw Hill’s prior consent. You
may use the work for your own noncommercial and personal use; any other use of the work is strictly prohibited. Your right to
use the work may be terminated if you fail to comply with these terms.
THE WORK IS PROVIDED “AS IS.” McGRAW HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRAN-
TIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING
THE WORK, INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK
OR OTHERWISE, AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT
LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
McGraw Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet your requirements
or that its operation will be uninterrupted or error free. Neither McGraw Hill nor its licensors shall be liable to you or anyone else
for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom. McGraw Hill has
no responsibility for the content of any information accessed through the work. Under no circumstances shall McGraw Hill and/
or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of
or inability to use the work, even if any of them has been advised of the possibility of such damages. This limitation of liability
shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tort or otherwise.
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For the young widows and widowers:
may they find the courage to face their fears,
to navigate their way through the pain,
and to find hope for a brighter future.
may they find the courage to face their fears,
to navigate their way through the pain,
and to find hope for a brighter future.
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ABOUT THE AUTHORS
Michael Jang (RHCE, LPIC-2, UCP, LCP, Linux+, MCP) is currently a Lead Technical
Writer for Forescout. His experience with computers goes back to the days of jumbled
punch cards. He has written other books on Linux certification, including LPIC-1 in
Depth, Mike Meyers’ Linux+ Certification Passport, and Sair GNU/Linux Installation and
Configuration Exam Cram. His other Linux books include Linux Annoyances for Geeks,
Linux Patch Management, and Security Strategies in Linux Platforms and Applications. He
has also written or contributed to books on Microsoft operating systems, including MCSE
Guide to Microsoft Windows 98 and Mastering Windows XP Professional, Second Edition.
Alessandro Orsaria (RHCE, RHCA, CCIE x 2) is an IT professional with more than
20 years’ experience in the industry. He has authored articles for technical Linux magazines
and is currently employed by a proprietary trading firm. Alessandro is Red Hat RHCE and
RHCA certified and has achieved two Cisco CCIE certifications in Routing & Switching and
Datacenter. He holds an MBA from Imperial College of London and a degree in physics.
About the Technical Editor
Sam Doran is a Principal Software Engineer at Red Hat. He served in the U.S. Air Force
as an aircraft mechanic and is a proud alumnus of the Virginia Tech Corps of Cadets.
Prior to joining Red Hat, he worked for the U.S. government as well as private industry in
jobs ranging from site reliability engineering to information security. He has used RHEL
professionally since 2003 as well as a number of other Linux distributions.
Michael Jang (RHCE, LPIC-2, UCP, LCP, Linux+, MCP) is currently a Lead Technical
Writer for Forescout. His experience with computers goes back to the days of jumbled
punch cards. He has written other books on Linux certification, including LPIC-1 in
Depth, Mike Meyers’ Linux+ Certification Passport, and Sair GNU/Linux Installation and
Configuration Exam Cram. His other Linux books include Linux Annoyances for Geeks,
Linux Patch Management, and Security Strategies in Linux Platforms and Applications. He
has also written or contributed to books on Microsoft operating systems, including MCSE
Guide to Microsoft Windows 98 and Mastering Windows XP Professional, Second Edition.
Alessandro Orsaria (RHCE, RHCA, CCIE x 2) is an IT professional with more than
20 years’ experience in the industry. He has authored articles for technical Linux magazines
and is currently employed by a proprietary trading firm. Alessandro is Red Hat RHCE and
RHCA certified and has achieved two Cisco CCIE certifications in Routing & Switching and
Datacenter. He holds an MBA from Imperial College of London and a degree in physics.
About the Technical Editor
Sam Doran is a Principal Software Engineer at Red Hat. He served in the U.S. Air Force
as an aircraft mechanic and is a proud alumnus of the Virginia Tech Corps of Cadets.
Prior to joining Red Hat, he worked for the U.S. government as well as private industry in
jobs ranging from site reliability engineering to information security. He has used RHEL
professionally since 2003 as well as a number of other Linux distributions.
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vii
CONTENTS AT A GLANCE
1 Prepare for the Red Hat RHCSA Certification ................................ 1
2 Fundamental Command-Line Skills ............................................. 43
3 Managing Basic Networking ...................................................... 91
4 Software Management ............................................................. 127
5 systemd and the Boot Process .................................................... 173
6 User Administration ................................................................ 215
7 Storage and Filesystem Administration ......................................... 253
8 Linux Security ........................................................................ 311
9 System Administration Tasks ..................................................... 353
10 An Introduction to Containers ................................................... 405
A Prepare a System for the Sample Exams ........................................ 447
B Solutions to RHCSA Sample Exam 1 ............................................ 451
C Solutions to RHCSA Sample Exam 2 ............................................ 459
D About the Online Content ......................................................... 467
Index ................................................................................... 471
CONTENTS AT A GLANCE
1 Prepare for the Red Hat RHCSA Certification ................................ 1
2 Fundamental Command-Line Skills ............................................. 43
3 Managing Basic Networking ...................................................... 91
4 Software Management ............................................................. 127
5 systemd and the Boot Process .................................................... 173
6 User Administration ................................................................ 215
7 Storage and Filesystem Administration ......................................... 253
8 Linux Security ........................................................................ 311
9 System Administration Tasks ..................................................... 353
10 An Introduction to Containers ................................................... 405
A Prepare a System for the Sample Exams ........................................ 447
B Solutions to RHCSA Sample Exam 1 ............................................ 451
C Solutions to RHCSA Sample Exam 2 ............................................ 459
D About the Online Content ......................................................... 467
Index ................................................................................... 471
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ix
CONTENTS
Acknowledgments ..................................................................... xix
Preface ................................................................................... xxi
Introduction ............................................................................ xxix
RHCSA Exam Readiness Checklist ................................................ xxxii
1 Prepare for the Red Hat RHCSA Certification ................. 1
The RHCSA Exam .................................................................. 4
The Exam Experience ................................................... 4
Evolving Requirements .................................................. 5
Basic Hardware Requirements .................................................... 5
Hardware Compatibility ................................................ 6
Architectures .............................................................. 6
RAM Requirements ...................................................... 7
Storage Options ........................................................... 7
Networking ................................................................ 8
Virtual Machine Options ............................................... 8
Get Red Hat Enterprise Linux .................................................... 9
Get a Subscription at No Cost ......................................... 10
Purchase a Subscription ................................................. 10
Third-Party Rebuilds .................................................... 10
Check the Download .................................................... 11
Exercise 1-1: Get Red Hat Enterprise Linux ..................... 12
An Environment for Practice Labs ............................................... 12
System Roles ............................................................... 14
Getting VMware Workstation Player ................................. 14
Virtual Networks on a Hypervisor .................................... 16
Configure a Virtual Machine on VMware Workstation Player ... 18
RHEL 9 Installation ................................................................. 22
Boot Media ................................................................ 22
Basic Installation Steps .................................................. 24
The Installation Perspective on Partitions ........................... 27
Partition Creation Exercise ............................................. 30
Exercise 1-2: Partitioning During Installation ................... 32
Wow, Look at All That Software! ...................................... 34
Baseline Packages ......................................................... 35
During the Installation .................................................. 35
CONTENTS
Acknowledgments ..................................................................... xix
Preface ................................................................................... xxi
Introduction ............................................................................ xxix
RHCSA Exam Readiness Checklist ................................................ xxxii
1 Prepare for the Red Hat RHCSA Certification ................. 1
The RHCSA Exam .................................................................. 4
The Exam Experience ................................................... 4
Evolving Requirements .................................................. 5
Basic Hardware Requirements .................................................... 5
Hardware Compatibility ................................................ 6
Architectures .............................................................. 6
RAM Requirements ...................................................... 7
Storage Options ........................................................... 7
Networking ................................................................ 8
Virtual Machine Options ............................................... 8
Get Red Hat Enterprise Linux .................................................... 9
Get a Subscription at No Cost ......................................... 10
Purchase a Subscription ................................................. 10
Third-Party Rebuilds .................................................... 10
Check the Download .................................................... 11
Exercise 1-1: Get Red Hat Enterprise Linux ..................... 12
An Environment for Practice Labs ............................................... 12
System Roles ............................................................... 14
Getting VMware Workstation Player ................................. 14
Virtual Networks on a Hypervisor .................................... 16
Configure a Virtual Machine on VMware Workstation Player ... 18
RHEL 9 Installation ................................................................. 22
Boot Media ................................................................ 22
Basic Installation Steps .................................................. 24
The Installation Perspective on Partitions ........................... 27
Partition Creation Exercise ............................................. 30
Exercise 1-2: Partitioning During Installation ................... 32
Wow, Look at All That Software! ...................................... 34
Baseline Packages ......................................................... 35
During the Installation .................................................. 35
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x RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
Initial Setup ................................................................ 36
Certification Summary .................................................. 37
✓ Two-Minute Drill ......................................................... 38
Q&A Self Test ..................................................................... 39
Lab Questions ............................................................. 40
Self Test Answers ......................................................... 41
Lab Answers ............................................................... 42
2 Fundamental Command-Line Skills ............................ 43
Shells ................................................................................... 46
Other Shells ............................................................... 46
Virtual Consoles .......................................................... 47
GUI Shell Interfaces ...................................................... 47
Differences Between Regular and Administrative Users .......... 49
Standard Streams and Command Redirection ..................... 49
Standard Command-Line Tools .................................................. 51
File and Directory Concepts ........................................... 52
File Lists and ls ............................................................ 54
File-Creation Commands ............................................... 55
Wildcards .................................................................. 58
File Searches ............................................................... 59
File Permissions ...................................................................... 60
File Permissions and Ownership ...................................... 60
Commands to Change Permissions and Ownership .............. 63
A Basic Introduction of User and Group Concepts ................ 66
Managing Text Files ................................................................. 68
Commands to Read Text Streams ..................................... 68
Commands to Process Text Streams .................................. 70
Edit Text Files at the Console .......................................... 73
Exercise 2-1: Using vi to Create a New User ..................... 75
If You Don’t Like vi ....................................................... 77
Edit Text Files in the GUI ............................................... 78
Accessing the Documentation .................................................... 78
When You Need Help ................................................... 79
A Variety of man Pages .................................................. 80
The info Manuals ......................................................... 81
Detailed Documentation in /usr/share/doc ......................... 81
Certification Summary .................................................. 82
✓ Two-Minute Drill ......................................................... 83
Q&A Self Test ..................................................................... 85
Lab Questions ............................................................. 86
Self Test Answers ......................................................... 86
Lab Answers ............................................................... 87
Initial Setup ................................................................ 36
Certification Summary .................................................. 37
✓ Two-Minute Drill ......................................................... 38
Q&A Self Test ..................................................................... 39
Lab Questions ............................................................. 40
Self Test Answers ......................................................... 41
Lab Answers ............................................................... 42
2 Fundamental Command-Line Skills ............................ 43
Shells ................................................................................... 46
Other Shells ............................................................... 46
Virtual Consoles .......................................................... 47
GUI Shell Interfaces ...................................................... 47
Differences Between Regular and Administrative Users .......... 49
Standard Streams and Command Redirection ..................... 49
Standard Command-Line Tools .................................................. 51
File and Directory Concepts ........................................... 52
File Lists and ls ............................................................ 54
File-Creation Commands ............................................... 55
Wildcards .................................................................. 58
File Searches ............................................................... 59
File Permissions ...................................................................... 60
File Permissions and Ownership ...................................... 60
Commands to Change Permissions and Ownership .............. 63
A Basic Introduction of User and Group Concepts ................ 66
Managing Text Files ................................................................. 68
Commands to Read Text Streams ..................................... 68
Commands to Process Text Streams .................................. 70
Edit Text Files at the Console .......................................... 73
Exercise 2-1: Using vi to Create a New User ..................... 75
If You Don’t Like vi ....................................................... 77
Edit Text Files in the GUI ............................................... 78
Accessing the Documentation .................................................... 78
When You Need Help ................................................... 79
A Variety of man Pages .................................................. 80
The info Manuals ......................................................... 81
Detailed Documentation in /usr/share/doc ......................... 81
Certification Summary .................................................. 82
✓ Two-Minute Drill ......................................................... 83
Q&A Self Test ..................................................................... 85
Lab Questions ............................................................. 86
Self Test Answers ......................................................... 86
Lab Answers ............................................................... 87
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Contents xi
3 Managing Basic Networking .................................... 91
A Networking Primer ............................................................... 93
IPv4 Networks ............................................................ 93
Networks and Routing ................................................... 94
Tools and Commands ................................................... 95
Network Configuration and Troubleshooting ................................. 101
Network Configuration Services ...................................... 101
Network Configuration Tools .......................................... 103
Exercise 3-1: Configure IPv4 Settings on a Network Interface ... 105
Configure Name Resolution ............................................ 109
Hostname Configuration Files ......................................... 109
An Introduction to IPv6 ........................................................... 111
Basic IPv6 Addressing ................................................... 111
Troubleshooting Tools .................................................. 113
Configure IPv6 Addresses .............................................. 114
Administration with Secure Shell and Secure Copy .......................... 115
Command-Line Access .................................................. 116
More SSH Command-Line Tools ..................................... 117
Graphical Secure Shell Access ......................................... 117
Certification Summary .................................................. 119
✓ Two-Minute Drill ......................................................... 119
Q&A Self Test ..................................................................... 120
Lab Questions ............................................................. 121
Self Test Answers ......................................................... 122
Lab Answers ............................................................... 123
4 Software Management .......................................... 127
The RPM Package Manager ....................................................... 129
What Is a Package? ....................................................... 129
What Is the RPM Database? ............................................ 130
What Is a Repository? ................................................... 130
Install an RPM Package ................................................. 131
Uninstall an RPM Package .............................................. 133
Install RPMs from Remote Systems ................................... 133
RPM Installation Security .............................................. 134
Updating the Kernel ..................................................... 134
More RPM Commands ............................................................. 136
Package Queries .......................................................... 137
Package Signatures ....................................................... 137
File Verification ........................................................... 138
Exercise 4-1: Practice with rpm Commands ..................... 140
3 Managing Basic Networking .................................... 91
A Networking Primer ............................................................... 93
IPv4 Networks ............................................................ 93
Networks and Routing ................................................... 94
Tools and Commands ................................................... 95
Network Configuration and Troubleshooting ................................. 101
Network Configuration Services ...................................... 101
Network Configuration Tools .......................................... 103
Exercise 3-1: Configure IPv4 Settings on a Network Interface ... 105
Configure Name Resolution ............................................ 109
Hostname Configuration Files ......................................... 109
An Introduction to IPv6 ........................................................... 111
Basic IPv6 Addressing ................................................... 111
Troubleshooting Tools .................................................. 113
Configure IPv6 Addresses .............................................. 114
Administration with Secure Shell and Secure Copy .......................... 115
Command-Line Access .................................................. 116
More SSH Command-Line Tools ..................................... 117
Graphical Secure Shell Access ......................................... 117
Certification Summary .................................................. 119
✓ Two-Minute Drill ......................................................... 119
Q&A Self Test ..................................................................... 120
Lab Questions ............................................................. 121
Self Test Answers ......................................................... 122
Lab Answers ............................................................... 123
4 Software Management .......................................... 127
The RPM Package Manager ....................................................... 129
What Is a Package? ....................................................... 129
What Is the RPM Database? ............................................ 130
What Is a Repository? ................................................... 130
Install an RPM Package ................................................. 131
Uninstall an RPM Package .............................................. 133
Install RPMs from Remote Systems ................................... 133
RPM Installation Security .............................................. 134
Updating the Kernel ..................................................... 134
More RPM Commands ............................................................. 136
Package Queries .......................................................... 137
Package Signatures ....................................................... 137
File Verification ........................................................... 138
Exercise 4-1: Practice with rpm Commands ..................... 140
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xii RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
Dependencies and the dnf Command ........................................... 141
An Example of Dependency Hell ...................................... 142
Relief from Dependency Hell .......................................... 143
Red Hat Subscription Management .................................. 144
Exercise 4-2: Subscribe a System to Red Hat
Subscription Management .......................................... 145
Basic dnf Configuration ................................................. 148
Exercise 4-3: Create a dnf Repository from the RHEL 9 DVD ... 152
Third-Party Repositories ................................................ 154
Exercise 4-4: Configure Access to the EPEL Repository ....... 154
Basic dnf Commands .................................................... 155
Installation Mode ......................................................... 155
Security and dnf .......................................................... 157
Updates and Security Fixes ............................................. 157
Package Groups and dnf ................................................ 157
More dnf Commands .................................................... 160
Module Streams (*) ................................................................. 162
Certification Summary .................................................. 165
✓ Two-Minute Drill ......................................................... 165
Q&A Self Test ..................................................................... 167
Lab Questions ............................................................. 168
Self Test Answers ......................................................... 168
Lab Answers ............................................................... 169
5 systemd and the Boot Process .................................. 173
The Boot Process .................................................................... 175
Basic System Configuration ............................................ 175
Startup Menus ............................................................ 176
Access to Linux Bootloaders ........................................... 176
Bootloaders and GRUB 2 .......................................................... 177
GRUB, the GRand Unified Bootloader ............................... 178
Exercise 5-1: Boot into a Different Target ........................ 180
Exercise 5-2: Recover the Root Password ......................... 181
Modify the System Bootloader ........................................ 182
How to Update GRUB 2 ................................................. 184
The GRUB 2 Command Line .......................................... 185
Exercise 5-3: Using the GRUB 2 Command Line ............... 186
An Option for Booting from GRUB 2: Rescue Mode .............. 187
Between GRUB 2 and Login ....................................................... 189
Kernels and the Initial RAM Disk ..................................... 190
The First Process, Targets, and Units ................................. 191
Switch Between Targets ................................................. 193
Dependencies and the dnf Command ........................................... 141
An Example of Dependency Hell ...................................... 142
Relief from Dependency Hell .......................................... 143
Red Hat Subscription Management .................................. 144
Exercise 4-2: Subscribe a System to Red Hat
Subscription Management .......................................... 145
Basic dnf Configuration ................................................. 148
Exercise 4-3: Create a dnf Repository from the RHEL 9 DVD ... 152
Third-Party Repositories ................................................ 154
Exercise 4-4: Configure Access to the EPEL Repository ....... 154
Basic dnf Commands .................................................... 155
Installation Mode ......................................................... 155
Security and dnf .......................................................... 157
Updates and Security Fixes ............................................. 157
Package Groups and dnf ................................................ 157
More dnf Commands .................................................... 160
Module Streams (*) ................................................................. 162
Certification Summary .................................................. 165
✓ Two-Minute Drill ......................................................... 165
Q&A Self Test ..................................................................... 167
Lab Questions ............................................................. 168
Self Test Answers ......................................................... 168
Lab Answers ............................................................... 169
5 systemd and the Boot Process .................................. 173
The Boot Process .................................................................... 175
Basic System Configuration ............................................ 175
Startup Menus ............................................................ 176
Access to Linux Bootloaders ........................................... 176
Bootloaders and GRUB 2 .......................................................... 177
GRUB, the GRand Unified Bootloader ............................... 178
Exercise 5-1: Boot into a Different Target ........................ 180
Exercise 5-2: Recover the Root Password ......................... 181
Modify the System Bootloader ........................................ 182
How to Update GRUB 2 ................................................. 184
The GRUB 2 Command Line .......................................... 185
Exercise 5-3: Using the GRUB 2 Command Line ............... 186
An Option for Booting from GRUB 2: Rescue Mode .............. 187
Between GRUB 2 and Login ....................................................... 189
Kernels and the Initial RAM Disk ..................................... 190
The First Process, Targets, and Units ................................. 191
Switch Between Targets ................................................. 193
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Contents xiii
Reboot and Shut Down a System Normally ......................... 193
systemd Replaces Upstart and SysVinit .............................. 194
systemd Units ............................................................. 197
Virtual Consoles and Login Screens .................................. 199
Control by Target .................................................................... 200
Functionality by Target .................................................. 200
The Innards of systemd Units .......................................... 201
Service Configuration ................................................... 203
Time Synchronization .............................................................. 204
Time Zone Configuration ............................................... 205
Sync the Time with chronyd ........................................... 206
Certification Summary .................................................. 207
✓ Two-Minute Drill ......................................................... 207
Q&A Self Test ..................................................................... 209
Lab Questions ............................................................. 210
Self Test Answers ......................................................... 210
Lab Answers ............................................................... 211
6 User Administration .............................................. 215
User Account Management ....................................................... 216
Different Kinds of Users ................................................. 217
The Shadow Password Suite ............................................ 218
Command-Line Tools ................................................... 225
Exercise 6-1: Add a User with Cockpit Web Console .......... 228
Exercise 6-2: Real and Fake Shells .................................. 230
Modify an Account ....................................................... 230
Administrative Control ............................................................. 232
The Ability to Log In ..................................................... 232
The su Command ........................................................ 233
Limit Access to su ........................................................ 234
The sg Command ......................................................... 234
Superuser Access with the sudo Command ......................... 234
User and Shell Configuration ..................................................... 236
Home Directories and /etc/skel ....................................... 236
Exercise 6-3: Another Way to Secure a System .................. 238
Shell Configuration Files in User Home Directories .............. 239
Login, Logout, and User Switching ................................... 239
Special Groups ....................................................................... 240
Standard and Red Hat Groups ......................................... 241
Shared Directories ....................................................... 241
Exercise 6-4: Control Group Ownership with the SGID Bit ... 242
Certification Summary .................................................. 244
✓ Two-Minute Drill ......................................................... 244
Reboot and Shut Down a System Normally ......................... 193
systemd Replaces Upstart and SysVinit .............................. 194
systemd Units ............................................................. 197
Virtual Consoles and Login Screens .................................. 199
Control by Target .................................................................... 200
Functionality by Target .................................................. 200
The Innards of systemd Units .......................................... 201
Service Configuration ................................................... 203
Time Synchronization .............................................................. 204
Time Zone Configuration ............................................... 205
Sync the Time with chronyd ........................................... 206
Certification Summary .................................................. 207
✓ Two-Minute Drill ......................................................... 207
Q&A Self Test ..................................................................... 209
Lab Questions ............................................................. 210
Self Test Answers ......................................................... 210
Lab Answers ............................................................... 211
6 User Administration .............................................. 215
User Account Management ....................................................... 216
Different Kinds of Users ................................................. 217
The Shadow Password Suite ............................................ 218
Command-Line Tools ................................................... 225
Exercise 6-1: Add a User with Cockpit Web Console .......... 228
Exercise 6-2: Real and Fake Shells .................................. 230
Modify an Account ....................................................... 230
Administrative Control ............................................................. 232
The Ability to Log In ..................................................... 232
The su Command ........................................................ 233
Limit Access to su ........................................................ 234
The sg Command ......................................................... 234
Superuser Access with the sudo Command ......................... 234
User and Shell Configuration ..................................................... 236
Home Directories and /etc/skel ....................................... 236
Exercise 6-3: Another Way to Secure a System .................. 238
Shell Configuration Files in User Home Directories .............. 239
Login, Logout, and User Switching ................................... 239
Special Groups ....................................................................... 240
Standard and Red Hat Groups ......................................... 241
Shared Directories ....................................................... 241
Exercise 6-4: Control Group Ownership with the SGID Bit ... 242
Certification Summary .................................................. 244
✓ Two-Minute Drill ......................................................... 244
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xiv RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
Q&A Self Test ..................................................................... 245
Lab Questions ............................................................. 246
Self Test Answers ......................................................... 246
Lab Answers ............................................................... 247
7 Storage and Filesystem Administration ....................... 253
Storage Management and Partitions ............................................. 255
Current System State .................................................... 255
The fdisk Utility ........................................................... 257
The gdisk Utility .......................................................... 264
The parted Utility ........................................................ 265
Using parted: Starting, Getting Help, and Quitting ............... 266
Graphical Options ........................................................ 271
Exercise 7-1: Work with fdisk and parted ......................... 272
Filesystem Formats .................................................................. 274
Standard Filesystems ..................................................... 275
Journaling Filesystems ................................................... 276
Filesystem Format Commands ......................................... 276
Swap Volumes ............................................................. 277
Filesystem Check Commands .......................................... 278
Exercise 7-2: Format, Check, and
Mount Different Filesystems ....................................... 278
Basic Linux Filesystems and Directories ........................................ 279
Separate Linux Filesystems ............................................. 279
Directories That Can Be Mounted Separately ...................... 281
Logical Volume Manager (LVM) ................................................. 282
Definitions in LVM ....................................................... 282
Create a Physical Volume ............................................... 283
Create a Volume Group ................................................. 283
Create a Logical Volume ................................................ 283
Make Use of a Logical Volume ......................................... 284
More LVM Commands .................................................. 284
Remove a Logical Volume .............................................. 287
Resize Logical Volumes ................................................. 287
Filesystem Management ........................................................... 288
The /etc/fstab File ........................................................ 288
Universally Unique Identifiers in /etc/fstab ......................... 290
The mount Command ................................................... 291
More Filesystem Mount Options ...................................... 292
Virtual Filesystems ....................................................... 293
Add Your Own Filesystems to /etc/fstab ............................. 293
Removable Media and /etc/fstab ...................................... 293
Network Filesystems ..................................................... 294
Q&A Self Test ..................................................................... 245
Lab Questions ............................................................. 246
Self Test Answers ......................................................... 246
Lab Answers ............................................................... 247
7 Storage and Filesystem Administration ....................... 253
Storage Management and Partitions ............................................. 255
Current System State .................................................... 255
The fdisk Utility ........................................................... 257
The gdisk Utility .......................................................... 264
The parted Utility ........................................................ 265
Using parted: Starting, Getting Help, and Quitting ............... 266
Graphical Options ........................................................ 271
Exercise 7-1: Work with fdisk and parted ......................... 272
Filesystem Formats .................................................................. 274
Standard Filesystems ..................................................... 275
Journaling Filesystems ................................................... 276
Filesystem Format Commands ......................................... 276
Swap Volumes ............................................................. 277
Filesystem Check Commands .......................................... 278
Exercise 7-2: Format, Check, and
Mount Different Filesystems ....................................... 278
Basic Linux Filesystems and Directories ........................................ 279
Separate Linux Filesystems ............................................. 279
Directories That Can Be Mounted Separately ...................... 281
Logical Volume Manager (LVM) ................................................. 282
Definitions in LVM ....................................................... 282
Create a Physical Volume ............................................... 283
Create a Volume Group ................................................. 283
Create a Logical Volume ................................................ 283
Make Use of a Logical Volume ......................................... 284
More LVM Commands .................................................. 284
Remove a Logical Volume .............................................. 287
Resize Logical Volumes ................................................. 287
Filesystem Management ........................................................... 288
The /etc/fstab File ........................................................ 288
Universally Unique Identifiers in /etc/fstab ......................... 290
The mount Command ................................................... 291
More Filesystem Mount Options ...................................... 292
Virtual Filesystems ....................................................... 293
Add Your Own Filesystems to /etc/fstab ............................. 293
Removable Media and /etc/fstab ...................................... 293
Network Filesystems ..................................................... 294
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Contents xv
The Automounter ................................................................... 296
Mounting via the Automounter ....................................... 296
Exercise 7-3: Configure the Automounter ........................ 300
Certification Summary .................................................. 301
✓ Two-Minute Drill ......................................................... 302
Q&A Self Test ..................................................................... 303
Lab Questions ............................................................. 304
Self Test Answers ......................................................... 305
Lab Answers ............................................................... 306
8 Linux Security ..................................................... 311
Basic Firewall Control .............................................................. 313
Standard Ports ............................................................ 314
The firewalld Service .................................................... 315
Exercise 8-1: Adjust Firewall Settings ............................. 320
Exercise 8-2: Firewall Configuration
with the Cockpit Web Console ..................................... 322
Securing SSH with Key-Based Authentication ................................ 324
SSH Configuration Commands ........................................ 324
SSH Client Configuration Files ........................................ 325
Basic Encrypted Communication ..................................... 325
Set Up a Private/Public Pair for Key-Based Authentication ..... 327
A Security-Enhanced Linux Primer ............................................. 329
Basic Features of SELinux ............................................... 329
SELinux Status ............................................................ 329
SELinux Configuration at the Command Line ..................... 331
Configure Basic SELinux Settings ..................................... 331
Configure Regular Users for SELinux ................................ 332
Manage SELinux Boolean Settings .................................... 334
List and Identify SELinux File Contexts .............................. 334
Restore SELinux File Contexts ......................................... 336
Exercise 8-3: Configure a New Directory
with Appropriate SELinux Contexts .............................. 337
SELinux Port Labeling ................................................... 338
Identify SELinux Process Contexts ................................... 338
Diagnose and Address SELinux Policy Violations ................. 339
The GUI SELinux Administration Tool .............................. 341
Certification Summary .................................................. 344
✓ Two-Minute Drill ......................................................... 345
Q&A Self Test ..................................................................... 346
Lab Questions ............................................................. 346
Self Test Answers ......................................................... 347
Lab Answers ............................................................... 348
The Automounter ................................................................... 296
Mounting via the Automounter ....................................... 296
Exercise 7-3: Configure the Automounter ........................ 300
Certification Summary .................................................. 301
✓ Two-Minute Drill ......................................................... 302
Q&A Self Test ..................................................................... 303
Lab Questions ............................................................. 304
Self Test Answers ......................................................... 305
Lab Answers ............................................................... 306
8 Linux Security ..................................................... 311
Basic Firewall Control .............................................................. 313
Standard Ports ............................................................ 314
The firewalld Service .................................................... 315
Exercise 8-1: Adjust Firewall Settings ............................. 320
Exercise 8-2: Firewall Configuration
with the Cockpit Web Console ..................................... 322
Securing SSH with Key-Based Authentication ................................ 324
SSH Configuration Commands ........................................ 324
SSH Client Configuration Files ........................................ 325
Basic Encrypted Communication ..................................... 325
Set Up a Private/Public Pair for Key-Based Authentication ..... 327
A Security-Enhanced Linux Primer ............................................. 329
Basic Features of SELinux ............................................... 329
SELinux Status ............................................................ 329
SELinux Configuration at the Command Line ..................... 331
Configure Basic SELinux Settings ..................................... 331
Configure Regular Users for SELinux ................................ 332
Manage SELinux Boolean Settings .................................... 334
List and Identify SELinux File Contexts .............................. 334
Restore SELinux File Contexts ......................................... 336
Exercise 8-3: Configure a New Directory
with Appropriate SELinux Contexts .............................. 337
SELinux Port Labeling ................................................... 338
Identify SELinux Process Contexts ................................... 338
Diagnose and Address SELinux Policy Violations ................. 339
The GUI SELinux Administration Tool .............................. 341
Certification Summary .................................................. 344
✓ Two-Minute Drill ......................................................... 345
Q&A Self Test ..................................................................... 346
Lab Questions ............................................................. 346
Self Test Answers ......................................................... 347
Lab Answers ............................................................... 348
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xvi RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
9 System Administration Tasks ................................... 353
Resource Management and System Tuning .................................... 355
System Resource Management Commands ......................... 355
System Tuning Profiles .................................................. 365
Archives and Compression ........................................................ 367
gzip and bzip2 ............................................................. 367
tar ............................................................................ 368
star .......................................................................... 368
Running Tasks on a Schedule: cron and at ..................................... 369
The System crontab and Components ............................... 369
Hourly cron Jobs .......................................................... 372
Regular anacron Jobs .................................................... 372
Setting Up cron for Users ............................................... 373
Exercise 9-1: Create a cron Job ..................................... 374
Running a Job with the at System ..................................... 374
Secure cron and at ........................................................ 375
Bash Scripts .......................................................................... 377
A “Hello, World” Script ................................................. 377
Bash Variables ............................................................. 378
Bash Control Structures ................................................. 381
Exercise 9-2: Create a Script ......................................... 386
Local Log Files ....................................................................... 388
System Log Configuration File ......................................... 389
Log File Management .................................................... 390
A Variety of Log Files .................................................... 391
Service-Specific Logs .................................................... 392
Exercise 9-3: Learn the Log Files ................................... 392
View systemd Journal Log Entries ..................................... 392
Certification Summary .................................................. 395
✓ Two-Minute Drill ......................................................... 396
Q&A Self Test ..................................................................... 397
Lab Questions ............................................................. 399
Self Test Answers ......................................................... 399
Lab Answers ............................................................... 400
10 An Introduction to Containers .................................. 405
Fundamentals of Container Technology ........................................ 407
The Rise of Container Technologies .................................. 407
Virtualization and Containers ......................................... 409
Understanding Container Architecture .............................. 410
Docker and Podman ..................................................... 411
9 System Administration Tasks ................................... 353
Resource Management and System Tuning .................................... 355
System Resource Management Commands ......................... 355
System Tuning Profiles .................................................. 365
Archives and Compression ........................................................ 367
gzip and bzip2 ............................................................. 367
tar ............................................................................ 368
star .......................................................................... 368
Running Tasks on a Schedule: cron and at ..................................... 369
The System crontab and Components ............................... 369
Hourly cron Jobs .......................................................... 372
Regular anacron Jobs .................................................... 372
Setting Up cron for Users ............................................... 373
Exercise 9-1: Create a cron Job ..................................... 374
Running a Job with the at System ..................................... 374
Secure cron and at ........................................................ 375
Bash Scripts .......................................................................... 377
A “Hello, World” Script ................................................. 377
Bash Variables ............................................................. 378
Bash Control Structures ................................................. 381
Exercise 9-2: Create a Script ......................................... 386
Local Log Files ....................................................................... 388
System Log Configuration File ......................................... 389
Log File Management .................................................... 390
A Variety of Log Files .................................................... 391
Service-Specific Logs .................................................... 392
Exercise 9-3: Learn the Log Files ................................... 392
View systemd Journal Log Entries ..................................... 392
Certification Summary .................................................. 395
✓ Two-Minute Drill ......................................................... 396
Q&A Self Test ..................................................................... 397
Lab Questions ............................................................. 399
Self Test Answers ......................................................... 399
Lab Answers ............................................................... 400
10 An Introduction to Containers .................................. 405
Fundamentals of Container Technology ........................................ 407
The Rise of Container Technologies .................................. 407
Virtualization and Containers ......................................... 409
Understanding Container Architecture .............................. 410
Docker and Podman ..................................................... 411
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Contents xvii
Getting Started with Containers ................................................. 412
Installing Container Tools .............................................. 412
Running Your First Container .......................................... 413
Rootless and Rootful Containers ...................................... 415
Building and Using Container Images ........................................... 416
Image Registries .......................................................... 416
Building Container Images: A Primer ................................ 418
Exercise 10-1: Building and Running a Container Image ...... 420
Exercise 10-2: Uploading an Image to Quay.io .................. 421
Managing Containers ............................................................... 422
Podman Commands ..................................................... 422
Running a Container as a SystemD Service ......................... 430
Exercise 10-3: Running a Container as a Service ................ 432
Persistent Storage ......................................................... 434
Exercise 10-4: Attaching Persistent Storage to a Container ... 435
Certification Summary .................................................. 436
✓ Two-Minute Drill ......................................................... 437
Q&A Self Test ..................................................................... 438
Lab Questions ............................................................. 439
Self Test Answers ......................................................... 440
Lab Answers ............................................................... 442
A Prepare a System for the Sample Exams ...................... 447
Sample Exam System Requirements ............................................. 447
B Solutions to RHCSA Sample Exam 1 ........................... 451
RHCSA Sample Exam 1 Discussion ............................................. 453
C Solutions to RHCSA Sample Exam 2 ........................... 459
RHCSA Sample Exam 2 Discussion ............................................. 461
D About the Online Content ....................................... 467
Single User License Terms and Conditions .................................... 467
Downloadable Book Resources ................................................... 469
Lab Files .................................................................... 469
Appendix A: Prepare a System for the Sample Exams ............ 469
Sample Exams ............................................................. 469
Technical Support ................................................................... 469
Index .............................................................. 471
Getting Started with Containers ................................................. 412
Installing Container Tools .............................................. 412
Running Your First Container .......................................... 413
Rootless and Rootful Containers ...................................... 415
Building and Using Container Images ........................................... 416
Image Registries .......................................................... 416
Building Container Images: A Primer ................................ 418
Exercise 10-1: Building and Running a Container Image ...... 420
Exercise 10-2: Uploading an Image to Quay.io .................. 421
Managing Containers ............................................................... 422
Podman Commands ..................................................... 422
Running a Container as a SystemD Service ......................... 430
Exercise 10-3: Running a Container as a Service ................ 432
Persistent Storage ......................................................... 434
Exercise 10-4: Attaching Persistent Storage to a Container ... 435
Certification Summary .................................................. 436
✓ Two-Minute Drill ......................................................... 437
Q&A Self Test ..................................................................... 438
Lab Questions ............................................................. 439
Self Test Answers ......................................................... 440
Lab Answers ............................................................... 442
A Prepare a System for the Sample Exams ...................... 447
Sample Exam System Requirements ............................................. 447
B Solutions to RHCSA Sample Exam 1 ........................... 451
RHCSA Sample Exam 1 Discussion ............................................. 453
C Solutions to RHCSA Sample Exam 2 ........................... 459
RHCSA Sample Exam 2 Discussion ............................................. 461
D About the Online Content ....................................... 467
Single User License Terms and Conditions .................................... 467
Downloadable Book Resources ................................................... 469
Lab Files .................................................................... 469
Appendix A: Prepare a System for the Sample Exams ............ 469
Sample Exams ............................................................. 469
Technical Support ................................................................... 469
Index .............................................................. 471
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xix
ACKNOWLEDGMENTS
I’d like to thank Ed Tittel, who gave me my first chance to write for publication, as well
as Tim Green, for helping me write what BookAuthority has named the best Red Hat
Linux book of all time! I’d also like to thank various mentors over the years: Penny Yao,
Susan Tacker, Mark Craig, and Carole Jelen for supporting my work. I’d also like to thank
Alessandro Orsaria for taking on the work required to update this book. We would not
have the last two editions without him. I’d like to pay tribute to my dog, Katie, who was
this man’s best friend for 15 years. Most importantly, I’d like to thank my sweet wife,
Donna; you are the love of my life.
—Mike Jang
My profound appreciation extends to Mike Jang and Tim Green, whose confidence in
my abilities enabled me to contribute to the eighth edition of this book. I also wish to
extend my gratitude to the editorial team of McGraw Hill, whose stellar efforts have been
indispensable. To Emiliano and Julia, whose unwavering support was my beacon during
the arduous process of creating this work, I offer my deepest thanks and love. A final
thought goes to Maria, for her constant support in all that I have done.
—Alessandro Orsaria
ACKNOWLEDGMENTS
I’d like to thank Ed Tittel, who gave me my first chance to write for publication, as well
as Tim Green, for helping me write what BookAuthority has named the best Red Hat
Linux book of all time! I’d also like to thank various mentors over the years: Penny Yao,
Susan Tacker, Mark Craig, and Carole Jelen for supporting my work. I’d also like to thank
Alessandro Orsaria for taking on the work required to update this book. We would not
have the last two editions without him. I’d like to pay tribute to my dog, Katie, who was
this man’s best friend for 15 years. Most importantly, I’d like to thank my sweet wife,
Donna; you are the love of my life.
—Mike Jang
My profound appreciation extends to Mike Jang and Tim Green, whose confidence in
my abilities enabled me to contribute to the eighth edition of this book. I also wish to
extend my gratitude to the editorial team of McGraw Hill, whose stellar efforts have been
indispensable. To Emiliano and Julia, whose unwavering support was my beacon during
the arduous process of creating this work, I offer my deepest thanks and love. A final
thought goes to Maria, for her constant support in all that I have done.
—Alessandro Orsaria
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xxi
PREFACE
Linux is booming, and Red Hat is leading this growth with the help of skilled Red Hat Certified
Systems Administrators (RHCSA).
Linux, which is free, became popular because it offered companies a cheaper alternative
to the more costly Unix systems. But Linux has more to offer than just cost savings. Thanks
to the Linux community, this operating system works well with many kinds of hardware.
Today, you can use Linux on everything from laptops and mobile devices to servers and
mainframes. This makes Linux a versatile option for many different situations.
Linux is also known for its strong security. Because it is open source, any security
problems can be quickly found and fixed by the community. Linux also has strong rules
about permissions and access, which makes it tough for harmful software to break in.
Regular updates also help keep Linux safe and secure.
Linux also provides good support for virtualization, which lets users create and manage
virtual machines (VMs) efficiently. With tools like Kernel-based Virtual Machine (KVM)
and Xen, Linux allows users to run more than one operating system at the same time on
a single machine. This is really useful in server environments, where virtualization makes
things like software deployment and resource management easier.
On top of this, Linux is the go-to platform for container technologies like Docker and
Kubernetes. Containers create isolated environments for applications, making them easier
to move and run on different systems. Linux’s built-in features, such as namespaces and
cgroups, are the backbone of containerization. These features make it easier to manage
resources, isolate processes, and scale up. By bringing together Linux and containerization,
software development and deployment have become faster and more efficient.
Having discussed the diverse capabilities and advantages of Linux, it’s essential to
recognize the challenges that come with mastering it. Red Hat exams, for instance, are
tough, and not many first-time test-takers pass the RHCSA exam. But don’t let that scare
you. While passing isn’t guaranteed, this book is designed to help you prepare for and
hopefully pass the RHCSA exam. The skills described in this book can also help you in
your job as a Linux administrator. However, this book isn’t a replacement for the Red Hat
prep courses, which we’ll talk about soon.
To prepare for the RHCSA exam, you should have a laptop or computer with at least
8GB of RAM so that you can run a couple of virtual machines. It doesn’t matter whether
your computer runs Linux, Windows, or macOS; you simply need to be able to create
two VMs. In this book, we use VMware Workstation Player as our hypervisor, but you
can choose another option like KVM, especially if you’re running Linux on your computer.
PREFACE
Linux is booming, and Red Hat is leading this growth with the help of skilled Red Hat Certified
Systems Administrators (RHCSA).
Linux, which is free, became popular because it offered companies a cheaper alternative
to the more costly Unix systems. But Linux has more to offer than just cost savings. Thanks
to the Linux community, this operating system works well with many kinds of hardware.
Today, you can use Linux on everything from laptops and mobile devices to servers and
mainframes. This makes Linux a versatile option for many different situations.
Linux is also known for its strong security. Because it is open source, any security
problems can be quickly found and fixed by the community. Linux also has strong rules
about permissions and access, which makes it tough for harmful software to break in.
Regular updates also help keep Linux safe and secure.
Linux also provides good support for virtualization, which lets users create and manage
virtual machines (VMs) efficiently. With tools like Kernel-based Virtual Machine (KVM)
and Xen, Linux allows users to run more than one operating system at the same time on
a single machine. This is really useful in server environments, where virtualization makes
things like software deployment and resource management easier.
On top of this, Linux is the go-to platform for container technologies like Docker and
Kubernetes. Containers create isolated environments for applications, making them easier
to move and run on different systems. Linux’s built-in features, such as namespaces and
cgroups, are the backbone of containerization. These features make it easier to manage
resources, isolate processes, and scale up. By bringing together Linux and containerization,
software development and deployment have become faster and more efficient.
Having discussed the diverse capabilities and advantages of Linux, it’s essential to
recognize the challenges that come with mastering it. Red Hat exams, for instance, are
tough, and not many first-time test-takers pass the RHCSA exam. But don’t let that scare
you. While passing isn’t guaranteed, this book is designed to help you prepare for and
hopefully pass the RHCSA exam. The skills described in this book can also help you in
your job as a Linux administrator. However, this book isn’t a replacement for the Red Hat
prep courses, which we’ll talk about soon.
To prepare for the RHCSA exam, you should have a laptop or computer with at least
8GB of RAM so that you can run a couple of virtual machines. It doesn’t matter whether
your computer runs Linux, Windows, or macOS; you simply need to be able to create
two VMs. In this book, we use VMware Workstation Player as our hypervisor, but you
can choose another option like KVM, especially if you’re running Linux on your computer.
Loading page 23...
xxii RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
You could also use cloud instances for the labs and exercises in this book, although some
cloud providers’ version of Red Hat Enterprise Linux might be slightly different from the
standard one. You might also be unable to do some tasks, like installing the operating system
from an ISO image. For these reasons, we recommend installing VMware Workstation Player,
as explained in Chapter 1, or another hypervisor of your choice.
Getting Red Hat Enterprise Linux
Red Hat exams, including the RHCSA, test your proficiency with Red Hat Enterprise Linux.
You might believe that you need to buy a subscription to RHEL to meet the exam objectives,
such as installing software packages and updates via Red Hat Subscription Management
(RHSM). However, Red Hat currently provides a no-cost Developer Subscription for
Individuals if you join the Red Hat Developer program. This subscription includes access to
Red Hat Enterprise Linux and a variety of other technologies. Joining the program, which you
can do for free at https://developers.redhat.com/register, is the only requirement. Chapter 1
provides detailed instructions on how to join and install Red Hat Enterprise Linux.
Alternatively, you can choose to install one of the many derivatives of Red Hat Enterprise
Linux. These derivatives are built from the RHEL source code, which is mostly released
under the Linux General Public License (GPL) or other open-source licenses. These licenses
grant anyone the right to construct Red Hat Enterprise Linux from the released Red Hat
source code. However, if you’re comfortable with the terms and conditions of the Red Hat
Developer program, there’s no clear advantage to using a derivative distribution for RHCSA
exam preparation.
Red Hat also provides several Enterprise Linux subscriptions. While not required for
RHCSA exam prep, familiarity with these can be beneficial if you plan to (or already) work
with Red Hat Enterprise Linux systems:
■■ RHEL Server provides varying levels of support for three different CPU architectures,
with costs based on the number of CPU sockets and supported virtual guests.
■■ RHEL Workstation includes varying levels of support ideal for workstation use.
■■ RHEL Developer Suite offers download access to RHEL 9 and several additional
software packages, intended solely for development.
■■ RHEL add-ons enhance functionality in areas such as high availability, resilient storage,
and load balancing, among others.
This book was developed using RHEL 9.1 Server. While RHEL’s source code is open
source, access to the binary packages requires a subscription. This can be free of charge if
you select the Red Hat Developer Subscription for Individuals.
You could also use cloud instances for the labs and exercises in this book, although some
cloud providers’ version of Red Hat Enterprise Linux might be slightly different from the
standard one. You might also be unable to do some tasks, like installing the operating system
from an ISO image. For these reasons, we recommend installing VMware Workstation Player,
as explained in Chapter 1, or another hypervisor of your choice.
Getting Red Hat Enterprise Linux
Red Hat exams, including the RHCSA, test your proficiency with Red Hat Enterprise Linux.
You might believe that you need to buy a subscription to RHEL to meet the exam objectives,
such as installing software packages and updates via Red Hat Subscription Management
(RHSM). However, Red Hat currently provides a no-cost Developer Subscription for
Individuals if you join the Red Hat Developer program. This subscription includes access to
Red Hat Enterprise Linux and a variety of other technologies. Joining the program, which you
can do for free at https://developers.redhat.com/register, is the only requirement. Chapter 1
provides detailed instructions on how to join and install Red Hat Enterprise Linux.
Alternatively, you can choose to install one of the many derivatives of Red Hat Enterprise
Linux. These derivatives are built from the RHEL source code, which is mostly released
under the Linux General Public License (GPL) or other open-source licenses. These licenses
grant anyone the right to construct Red Hat Enterprise Linux from the released Red Hat
source code. However, if you’re comfortable with the terms and conditions of the Red Hat
Developer program, there’s no clear advantage to using a derivative distribution for RHCSA
exam preparation.
Red Hat also provides several Enterprise Linux subscriptions. While not required for
RHCSA exam prep, familiarity with these can be beneficial if you plan to (or already) work
with Red Hat Enterprise Linux systems:
■■ RHEL Server provides varying levels of support for three different CPU architectures,
with costs based on the number of CPU sockets and supported virtual guests.
■■ RHEL Workstation includes varying levels of support ideal for workstation use.
■■ RHEL Developer Suite offers download access to RHEL 9 and several additional
software packages, intended solely for development.
■■ RHEL add-ons enhance functionality in areas such as high availability, resilient storage,
and load balancing, among others.
This book was developed using RHEL 9.1 Server. While RHEL’s source code is open
source, access to the binary packages requires a subscription. This can be free of charge if
you select the Red Hat Developer Subscription for Individuals.
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Preface xxiii
Enterprise-level operating systems like RHEL 9 offer the benefit of stability. When an
enterprise upgrades to RHEL 9, they can trust that configuration revisions will be a one-
time affair, with security updates and bug fixes handled automatically. Red Hat strives
to ensure enterprises won’t need to overhaul their systems for minor releases, such as
RHEL 9.1. A necessity to reconfigure for minor updates would escalate costs.
Minor releases also should not impact Red Hat exam objectives. While RHEL 9.2 introduces
bug fixes, security updates, and new features, it doesn’t alter the defaults of any configuration
files detailed in this book.
We expect future minor releases, such as RHEL 9.3, RHEL 9.4, and beyond, to follow
this pattern. Our close monitoring of RHEL releases over the past ten years suggests no
significant exam objective changes based solely on a minor release. Still, you should routinely
check the exam objectives listed on the Red Hat website to ensure they align with the content
of this study guide.
In This Book
Chapter 1 of this book is designed to assist you in preparing a study system for the RHCSA
exam and offers detailed insight into the exam experience.
Except for Chapter 1, every chapter begins by outlining the objectives pertinent to that
chapter’s material. Following this, the topics are dissected and explained. We have chosen
to present the topics in an order that we believe will be most beneficial to the majority of
candidates, which doesn’t necessarily follow the sequence of the exam objectives. However,
if you are already well-versed with Linux, feel free to skip over certain sections or entire
chapters during your initial reading.
Toward the end of each chapter, we’ve included a Self Test, a series of questions, along with
their answers. While Red Hat exams don’t typically involve multiple-choice questions, these
types of questions can still be a valuable tool in assessing your understanding and retention
of the chapter material. Furthermore, the short-answer questions format emphasizes the
practical experience necessary for the exam.
Following this Self Test is a “Lab Questions” section that directs you to the companion
website to access the lab exercises for the chapter. The solutions to the lab exercises
are included in the book, at the end of each chapter. Please see Appendix D, “About the
Online Content.”
Remember, Red Hat exams are hands-on. Therefore, practice is key. You should
repeatedly exercise your skills until you reach a level of confidence where you can complete
tasks without the assistance of this book. The Red Hat RHCSA exam is designed to test
candidate qualifications as Linux systems administrators. If you pass the exam, it’s not
because you’ve memorized a canned set of answers—it’s because you have a set of Linux
administrative skills and know how to use them under pressure, whether it be during an
exam or in a real-world situation.
Enterprise-level operating systems like RHEL 9 offer the benefit of stability. When an
enterprise upgrades to RHEL 9, they can trust that configuration revisions will be a one-
time affair, with security updates and bug fixes handled automatically. Red Hat strives
to ensure enterprises won’t need to overhaul their systems for minor releases, such as
RHEL 9.1. A necessity to reconfigure for minor updates would escalate costs.
Minor releases also should not impact Red Hat exam objectives. While RHEL 9.2 introduces
bug fixes, security updates, and new features, it doesn’t alter the defaults of any configuration
files detailed in this book.
We expect future minor releases, such as RHEL 9.3, RHEL 9.4, and beyond, to follow
this pattern. Our close monitoring of RHEL releases over the past ten years suggests no
significant exam objective changes based solely on a minor release. Still, you should routinely
check the exam objectives listed on the Red Hat website to ensure they align with the content
of this study guide.
In This Book
Chapter 1 of this book is designed to assist you in preparing a study system for the RHCSA
exam and offers detailed insight into the exam experience.
Except for Chapter 1, every chapter begins by outlining the objectives pertinent to that
chapter’s material. Following this, the topics are dissected and explained. We have chosen
to present the topics in an order that we believe will be most beneficial to the majority of
candidates, which doesn’t necessarily follow the sequence of the exam objectives. However,
if you are already well-versed with Linux, feel free to skip over certain sections or entire
chapters during your initial reading.
Toward the end of each chapter, we’ve included a Self Test, a series of questions, along with
their answers. While Red Hat exams don’t typically involve multiple-choice questions, these
types of questions can still be a valuable tool in assessing your understanding and retention
of the chapter material. Furthermore, the short-answer questions format emphasizes the
practical experience necessary for the exam.
Following this Self Test is a “Lab Questions” section that directs you to the companion
website to access the lab exercises for the chapter. The solutions to the lab exercises
are included in the book, at the end of each chapter. Please see Appendix D, “About the
Online Content.”
Remember, Red Hat exams are hands-on. Therefore, practice is key. You should
repeatedly exercise your skills until you reach a level of confidence where you can complete
tasks without the assistance of this book. The Red Hat RHCSA exam is designed to test
candidate qualifications as Linux systems administrators. If you pass the exam, it’s not
because you’ve memorized a canned set of answers—it’s because you have a set of Linux
administrative skills and know how to use them under pressure, whether it be during an
exam or in a real-world situation.
Loading page 25...
xxiv RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
While this book is organized to serve as an in-depth review for the RHCSA exam for
both experienced Linux and Unix professionals, it is not intended as a substitute for Red Hat
courses—or, more important, real-world experience. Nevertheless, each chapter covers a
major aspect of the exam, with an emphasis on the “why” as well as the “how to” of working
with and supporting RHEL as a systems administrator or engineer.
Conventions and Abbreviations
Although logging in to the root user account is a risky practice on production systems, it is
the fastest way to administer RHEL during the exam. The command prompt assumes use of
that account. When logged in to the root account, you’ll see a command-line prompt similar
to the following:
[root@server1 root]#
As the length of this prompt would lead to a number of broken and wrapped code lines
throughout this book, we’ve normally abbreviated the root account prompt as
#
Be careful. The hash mark (#) is also used as a comment character in Linux scripts and
programs. When logged in as a regular user, you will see a slightly different prompt; for user
michael, it would typically look like the following:
[michael@server1 michael]$
Similarly, we’ve abbreviated this as
$
There are a number of command lines and blocks of code interspersed throughout the
chapters. Commands embedded within regular text, such as ls -l, are shown in bold. User
entries and some variables in regular text are also shown in bold.
Sometimes commands exceed the available length of a line. Take this example:
# virt-install -n outsider1.example.org -r 1024 --disk
path=/var/lib/libvirt/images/outsider1.example.org.img,size=16
-l ftp://192.168.122.1/pub/inst -x ks=ftp://192.168.122.1/pub/ks1.cfg
Unless this command is carefully formatted, line breaks might appear in unfortunate
places, such as between the two dashes in front of the --disk switch. One way to address
this is with the backslash (\), which “escapes” the meaning of the carriage return that
follows. (The backslash can also “escape” the meaning of a space, making it easier to work
While this book is organized to serve as an in-depth review for the RHCSA exam for
both experienced Linux and Unix professionals, it is not intended as a substitute for Red Hat
courses—or, more important, real-world experience. Nevertheless, each chapter covers a
major aspect of the exam, with an emphasis on the “why” as well as the “how to” of working
with and supporting RHEL as a systems administrator or engineer.
Conventions and Abbreviations
Although logging in to the root user account is a risky practice on production systems, it is
the fastest way to administer RHEL during the exam. The command prompt assumes use of
that account. When logged in to the root account, you’ll see a command-line prompt similar
to the following:
[root@server1 root]#
As the length of this prompt would lead to a number of broken and wrapped code lines
throughout this book, we’ve normally abbreviated the root account prompt as
#
Be careful. The hash mark (#) is also used as a comment character in Linux scripts and
programs. When logged in as a regular user, you will see a slightly different prompt; for user
michael, it would typically look like the following:
[michael@server1 michael]$
Similarly, we’ve abbreviated this as
$
There are a number of command lines and blocks of code interspersed throughout the
chapters. Commands embedded within regular text, such as ls -l, are shown in bold. User
entries and some variables in regular text are also shown in bold.
Sometimes commands exceed the available length of a line. Take this example:
# virt-install -n outsider1.example.org -r 1024 --disk
path=/var/lib/libvirt/images/outsider1.example.org.img,size=16
-l ftp://192.168.122.1/pub/inst -x ks=ftp://192.168.122.1/pub/ks1.cfg
Unless this command is carefully formatted, line breaks might appear in unfortunate
places, such as between the two dashes in front of the --disk switch. One way to address
this is with the backslash (\), which “escapes” the meaning of the carriage return that
follows. (The backslash can also “escape” the meaning of a space, making it easier to work
Loading page 26...
Preface xxv
with multiple-word filenames.) Therefore, while the following command appears as if it is
on four different lines, the backslashes mean that Linux reads it as one single command:
# virt-install -n outsider1.example.org -r 1024 --disk \
> path=/var/lib/libvirt/images/outsider1.example.org.img,size=16 \
> -l ftp://192.168.122.1/pub/inst \
> -x ks=ftp://192.168.122.1/pub/ks1.cfg
In some code snippets, we could not use the backslash character to split the output on
more than one line. In those cases, we used a continuation arrow, as shown next:
5 2 * * 6 root /usr/bin/tar --selinux -czf /tmp/etc-backup-\$(/bin/date
+\%m\%d).tar.gz /etc > /dev/null
Sometimes, you’ll need to actually type in a command or a response to a question at a
command line. In that case, you’ll see an instruction such as “Type y.” Alternatively, some
menus require a keypress; for instance, you may be asked to press p to access a password
prompt. In that case, the letter p is not added to the screen when you press that key. In
addition, the a, despite its appearances, is in lowercase. In contrast, A is the uppercase
version of that letter.
One area where some publishers have trouble is with the double-dash. Some publishing
programs change the double-dash to an em dash (—). But that can be a problem. The double-
dash is common in many Linux commands. For example, the following command lists all
packages currently installed on the local system:
# rpm --query --all
When we ran this command on our RHEL 9 systems, it listed over 1000 packages.
In contrast, the following command lists all files in all packages on the local system:
# rpm --query -all
When we ran this command on our RHEL 9 system, it listed over 150,000 files, a rather
different result. So pay attention to the dashes, and rest assured that the team who produced
this book took care to make sure that double-dashes are shown as is!
Exam Readiness Checklist
At the end of the Introduction, you will find an Exam Readiness Checklist. This table has
been constructed to allow you to cross-reference the official RHCSA exam objectives with
the objectives as they are presented and covered in this book. The checklist also allows
you to gauge your level of expertise on each objective at the outset of your studies. This
should allow you to check your progress and make sure you spend the time you need on
more difficult or unfamiliar sections. The checklist lists all the objectives exactly as Red
Hat presents them (www.redhat.com/en/services/training/ex200-red-hat-certified-system-
administrator-rhcsa-exam?section=objectives) and cross-references the corresponding
with multiple-word filenames.) Therefore, while the following command appears as if it is
on four different lines, the backslashes mean that Linux reads it as one single command:
# virt-install -n outsider1.example.org -r 1024 --disk \
> path=/var/lib/libvirt/images/outsider1.example.org.img,size=16 \
> -l ftp://192.168.122.1/pub/inst \
> -x ks=ftp://192.168.122.1/pub/ks1.cfg
In some code snippets, we could not use the backslash character to split the output on
more than one line. In those cases, we used a continuation arrow, as shown next:
5 2 * * 6 root /usr/bin/tar --selinux -czf /tmp/etc-backup-\$(/bin/date
+\%m\%d).tar.gz /etc > /dev/null
Sometimes, you’ll need to actually type in a command or a response to a question at a
command line. In that case, you’ll see an instruction such as “Type y.” Alternatively, some
menus require a keypress; for instance, you may be asked to press p to access a password
prompt. In that case, the letter p is not added to the screen when you press that key. In
addition, the a, despite its appearances, is in lowercase. In contrast, A is the uppercase
version of that letter.
One area where some publishers have trouble is with the double-dash. Some publishing
programs change the double-dash to an em dash (—). But that can be a problem. The double-
dash is common in many Linux commands. For example, the following command lists all
packages currently installed on the local system:
# rpm --query --all
When we ran this command on our RHEL 9 systems, it listed over 1000 packages.
In contrast, the following command lists all files in all packages on the local system:
# rpm --query -all
When we ran this command on our RHEL 9 system, it listed over 150,000 files, a rather
different result. So pay attention to the dashes, and rest assured that the team who produced
this book took care to make sure that double-dashes are shown as is!
Exam Readiness Checklist
At the end of the Introduction, you will find an Exam Readiness Checklist. This table has
been constructed to allow you to cross-reference the official RHCSA exam objectives with
the objectives as they are presented and covered in this book. The checklist also allows
you to gauge your level of expertise on each objective at the outset of your studies. This
should allow you to check your progress and make sure you spend the time you need on
more difficult or unfamiliar sections. The checklist lists all the objectives exactly as Red
Hat presents them (www.redhat.com/en/services/training/ex200-red-hat-certified-system-
administrator-rhcsa-exam?section=objectives) and cross-references the corresponding
Loading page 27...
xxvi RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
coverage in this book, including chapter and page references. Additionally, the table features
a column of blank boxes next to each objective. Readers can check these boxes when they
feel confident that they are prepared for that specific exam objective.
In Every Chapter
For this series, we’ve created a set of chapter components that calls your attention to
important items, reinforces important points, and provides helpful exam-taking hints.
Take a look at what you’ll find in every chapter:
■■ Every chapter begins with the Certification Objectives—the skills you need to
master in order to pass the section on the exam associated with the chapter topic.
The Objective headings identify the objectives within the chapter, so you’ll always
know an objective when you see it.
■■ Exam Watch notes call attention to information about, and potential pitfalls in,
the exam. These helpful hints are written by authors who have taken the exams and
received their certification—who better to tell you what to worry about? They know
what you’re about to go through!
This book’s coverage of the
RHCSA exam objectives can be found in the
RHCSA Exam Readiness Checklist at the end
of this front matter.
■■ Practice Exercises are interspersed throughout the chapters. These are step-by-step
exercises that allow you to get the hands-on experience you need in order to pass the
exams. They help you master skills that are likely to be an area of focus on the exam.
Don’t just read through the exercises; they are hands-on practice that you should
be comfortable completing. Learning by doing is an effective way to increase your
competency with a product. Remember, the Red Hat exams are entirely “hands on”;
there are no multiple-choice questions on these exams.
■■ On the Job notes describe the issues that come up most often in real-world settings.
They provide a valuable perspective on certification- and product-related topics.
They point out common mistakes and address questions that have arisen from on-
the-job discussions and experience.
■■ Inside the Exam sidebars highlight some of the most common and confusing problems
that students encounter when taking a live exam. Designed to anticipate what the exam
will emphasize, they will help ensure you know what you need to know to pass the
exam. You can get a leg up on how to respond to those difficult-to-understand labs by
focusing extra attention on these sidebars.
coverage in this book, including chapter and page references. Additionally, the table features
a column of blank boxes next to each objective. Readers can check these boxes when they
feel confident that they are prepared for that specific exam objective.
In Every Chapter
For this series, we’ve created a set of chapter components that calls your attention to
important items, reinforces important points, and provides helpful exam-taking hints.
Take a look at what you’ll find in every chapter:
■■ Every chapter begins with the Certification Objectives—the skills you need to
master in order to pass the section on the exam associated with the chapter topic.
The Objective headings identify the objectives within the chapter, so you’ll always
know an objective when you see it.
■■ Exam Watch notes call attention to information about, and potential pitfalls in,
the exam. These helpful hints are written by authors who have taken the exams and
received their certification—who better to tell you what to worry about? They know
what you’re about to go through!
This book’s coverage of the
RHCSA exam objectives can be found in the
RHCSA Exam Readiness Checklist at the end
of this front matter.
■■ Practice Exercises are interspersed throughout the chapters. These are step-by-step
exercises that allow you to get the hands-on experience you need in order to pass the
exams. They help you master skills that are likely to be an area of focus on the exam.
Don’t just read through the exercises; they are hands-on practice that you should
be comfortable completing. Learning by doing is an effective way to increase your
competency with a product. Remember, the Red Hat exams are entirely “hands on”;
there are no multiple-choice questions on these exams.
■■ On the Job notes describe the issues that come up most often in real-world settings.
They provide a valuable perspective on certification- and product-related topics.
They point out common mistakes and address questions that have arisen from on-
the-job discussions and experience.
■■ Inside the Exam sidebars highlight some of the most common and confusing problems
that students encounter when taking a live exam. Designed to anticipate what the exam
will emphasize, they will help ensure you know what you need to know to pass the
exam. You can get a leg up on how to respond to those difficult-to-understand labs by
focusing extra attention on these sidebars.
Loading page 28...
Preface xxvii
■■ Scenario & Solution sections lay out potential problems and solutions in a quick-to-
read format.
■■ The Certification Summary is a succinct review of the chapter and a restatement of
salient skills regarding the exam.
■■ The Two-Minute Drill at the end of every chapter is a checklist of the main points
of the chapter. It can be used for last-minute review.
■■ The Self Test offers questions designed to help test the practical knowledge associated
with the certification exams. The answers to these questions, as well as explanations
of the answers, can be found at the end of each chapter. By taking the Self Test after
completing each chapter, you’ll reinforce what you’ve learned from that chapter. This
book does not include multiple-choice questions because Red Hat does not include any
such questions on its exams.
■■ The Lab Questions at the end of the Self Test section offer a unique and challenging
question format that requires the reader to understand multiple chapter concepts to
answer correctly. These questions are more complex and more comprehensive than the
other questions because they test your ability to take all the knowledge you have gained
from reading the chapter and apply it to complicated, real-world situations. Starting
with Chapter 2, all lab questions are available only from the companion website that
accompanies this book, consistent with the electronic format associated with the Red
Hat exams. Remember, the Red Hat exams contain only lab-type questions. If you can
answer these questions, you have proven that you know the subject!
Additional Resources
If you would like to pursue further reading beyond this book, perhaps the best way to do so
is with Red Hat documentation. Much of what we’ve learned about RHEL 9 comes from the
documents available at https://access.redhat.com/documentation/en/red_hat_enterprise_
linux/9. For your purposes, the following may be the most important of these guides:
■■ Performing a Standard RHEL 9 Installation Although Red Hat exams are given
on preconfigured systems, every Linux administrator should be able to install the
operating system from scratch.
■■ Configuring Basic System Settings This system administrator guide includes
essential skills that you should be able to master in your job.
■■ Managing Software with the DNF Tool This guide could serve as an additional
resource that expands upon the software installation procedures detailed in Chapter 4.
■■ Using SELinux SELinux often poses a challenging topic for many candidates. This
guide details various strategies that can aid in bolstering your SELinux policy’s security.
■■ Configuring and Managing Networking Despite a majority of this guide’s chapters
being beyond the scope of the RHCSA exam, the initial chapters establish a strong
foundation on network configuration.
✓
Q&A
■■ Scenario & Solution sections lay out potential problems and solutions in a quick-to-
read format.
■■ The Certification Summary is a succinct review of the chapter and a restatement of
salient skills regarding the exam.
■■ The Two-Minute Drill at the end of every chapter is a checklist of the main points
of the chapter. It can be used for last-minute review.
■■ The Self Test offers questions designed to help test the practical knowledge associated
with the certification exams. The answers to these questions, as well as explanations
of the answers, can be found at the end of each chapter. By taking the Self Test after
completing each chapter, you’ll reinforce what you’ve learned from that chapter. This
book does not include multiple-choice questions because Red Hat does not include any
such questions on its exams.
■■ The Lab Questions at the end of the Self Test section offer a unique and challenging
question format that requires the reader to understand multiple chapter concepts to
answer correctly. These questions are more complex and more comprehensive than the
other questions because they test your ability to take all the knowledge you have gained
from reading the chapter and apply it to complicated, real-world situations. Starting
with Chapter 2, all lab questions are available only from the companion website that
accompanies this book, consistent with the electronic format associated with the Red
Hat exams. Remember, the Red Hat exams contain only lab-type questions. If you can
answer these questions, you have proven that you know the subject!
Additional Resources
If you would like to pursue further reading beyond this book, perhaps the best way to do so
is with Red Hat documentation. Much of what we’ve learned about RHEL 9 comes from the
documents available at https://access.redhat.com/documentation/en/red_hat_enterprise_
linux/9. For your purposes, the following may be the most important of these guides:
■■ Performing a Standard RHEL 9 Installation Although Red Hat exams are given
on preconfigured systems, every Linux administrator should be able to install the
operating system from scratch.
■■ Configuring Basic System Settings This system administrator guide includes
essential skills that you should be able to master in your job.
■■ Managing Software with the DNF Tool This guide could serve as an additional
resource that expands upon the software installation procedures detailed in Chapter 4.
■■ Using SELinux SELinux often poses a challenging topic for many candidates. This
guide details various strategies that can aid in bolstering your SELinux policy’s security.
■■ Configuring and Managing Networking Despite a majority of this guide’s chapters
being beyond the scope of the RHCSA exam, the initial chapters establish a strong
foundation on network configuration.
✓
Q&A
Loading page 29...
xxviii RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
Some Pointers
Once you’ve finished reading this book, set aside some time to do a thorough review. You
might want to return to the book several times and make use of all the methods it offers for
reviewing the material:
■■ Reread all the Exam Watch notes. Remember that these notes are written by authors
who have taken the exam and passed. They know what you should expect—and what
you should be on the lookout for.
■■ Review all the Scenario & Solution sections for quick problem solving.
■■ Retake the Self Tests. Focus on the labs, as there are no multiple-choice questions
on the Red Hat exams. We’ve included questions just to test your mastery of the
practical material in each chapter.
■■ Complete the exercises. Did you do the exercises when you read through each
chapter? If not, do them! These exercises are designed to cover exam topics, and
there’s no better way to get to know this material than by practicing. Be sure you
understand why you are performing each step in each exercise. If there is something
you are not clear on, reread that section in the chapter.
Some Pointers
Once you’ve finished reading this book, set aside some time to do a thorough review. You
might want to return to the book several times and make use of all the methods it offers for
reviewing the material:
■■ Reread all the Exam Watch notes. Remember that these notes are written by authors
who have taken the exam and passed. They know what you should expect—and what
you should be on the lookout for.
■■ Review all the Scenario & Solution sections for quick problem solving.
■■ Retake the Self Tests. Focus on the labs, as there are no multiple-choice questions
on the Red Hat exams. We’ve included questions just to test your mastery of the
practical material in each chapter.
■■ Complete the exercises. Did you do the exercises when you read through each
chapter? If not, do them! These exercises are designed to cover exam topics, and
there’s no better way to get to know this material than by practicing. Be sure you
understand why you are performing each step in each exercise. If there is something
you are not clear on, reread that section in the chapter.
Loading page 30...
xxix
INTRODUCTION
The Red Hat Exam Challenge
This section covers the reasons for pursuing industry-recognized certification, explains the
importance of the RHCSA certification, and prepares you for taking the actual examination.
It gives you a few pointers on how to prepare, what to expect, and what to do on exam day.
This book covers every published exam objective at the time of writing. For the latest
objectives, see www.redhat.com/en/services/certification/rhcsa. Red Hat has also published
a syllabus for each of its prep courses for these exams, described shortly. While the published
exam objectives are accurate, the prep course syllabi provide additional information. Each
Red Hat prep course provides an excellent grounding in systems administration, network
administration, security, and more. To that end, this book also includes coverage based on the
public syllabi of Red Hat courses RH124 and RH134, described later.
Nevertheless, this book is not intended to be a substitute for any Red Hat course.
Leaping Ahead of the Competition!
Red Hat’s RHCSA certification exam is a hands-on exam. As such, it is respected
throughout the industry as a sign of genuine practical knowledge. If you pass, you will
be head and shoulders above the candidate who has passed only a “standard” multiple-
choice certification exam.
Red Hat has offered its hands-on exams since 1999. They’ve evolved over the years. As
detailed in Chapter 1, the RHCSA is a three-hour exam. The requirements are detailed in
the Exam Readiness Checklist later in this Introduction.
Why a Hands-On Exam?
Most certifications today are based on multiple-choice exams. These types of exams are
relatively inexpensive to set up and easy to proctor. Unfortunately, many people without
real-world skills are good at taking multiple-choice exams. In some cases, the answers to
these multiple-choice exams are already available online. This results in problems on the
job with “certified” engineers who have an image as “paper tigers” and do not have any
real-world skills.
INTRODUCTION
The Red Hat Exam Challenge
This section covers the reasons for pursuing industry-recognized certification, explains the
importance of the RHCSA certification, and prepares you for taking the actual examination.
It gives you a few pointers on how to prepare, what to expect, and what to do on exam day.
This book covers every published exam objective at the time of writing. For the latest
objectives, see www.redhat.com/en/services/certification/rhcsa. Red Hat has also published
a syllabus for each of its prep courses for these exams, described shortly. While the published
exam objectives are accurate, the prep course syllabi provide additional information. Each
Red Hat prep course provides an excellent grounding in systems administration, network
administration, security, and more. To that end, this book also includes coverage based on the
public syllabi of Red Hat courses RH124 and RH134, described later.
Nevertheless, this book is not intended to be a substitute for any Red Hat course.
Leaping Ahead of the Competition!
Red Hat’s RHCSA certification exam is a hands-on exam. As such, it is respected
throughout the industry as a sign of genuine practical knowledge. If you pass, you will
be head and shoulders above the candidate who has passed only a “standard” multiple-
choice certification exam.
Red Hat has offered its hands-on exams since 1999. They’ve evolved over the years. As
detailed in Chapter 1, the RHCSA is a three-hour exam. The requirements are detailed in
the Exam Readiness Checklist later in this Introduction.
Why a Hands-On Exam?
Most certifications today are based on multiple-choice exams. These types of exams are
relatively inexpensive to set up and easy to proctor. Unfortunately, many people without
real-world skills are good at taking multiple-choice exams. In some cases, the answers to
these multiple-choice exams are already available online. This results in problems on the
job with “certified” engineers who have an image as “paper tigers” and do not have any
real-world skills.
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