Red Hat RHCSA 9 Cert Guide

Introduction xxx
Part I Performing Basic System Management Tasks
Chapter 1 Installing Red Hat Enterprise Linux 3
“Do I Know This Already?” Quiz 3
Foundation Topics 6
Preparing to Install Red Hat Enterprise Linux 6
What Is Red Hat Enterprise Linux 9 Server? 6
Getting the Software 7
Using Red Hat Enterprise Linux 7
Using CentOS Stream 7
Other Distributions 8
Understanding Access to Repositories 8
Setup Requirements 9
Cert Guide Environment Description 9
Performing an Installation 10
Summary 22
Exam Preparation Tasks 23
End-of-Chapter Lab 24
Chapter 2 Using Essential Tools 27
“Do I Know This Already?” Quiz 27
Foundation Topics 30
Basic Shell Skills 30
Understanding Commands 30
Executing Commands 30
I/O Redirection 32
Using Pipes 34
History 35
Bash Completion 37
Editing Files with vim 37
Understanding the Shell Environment 40
Understanding Variables 40
Recognizing Environment Configuration Files 41
Using /etc/motd and /etc/issue 42
Finding Help 43
Using --help 43
Using man 43
Finding the Right man Page 44
Updating mandb 46
Using info 47
Using /usr/share/doc Documentation Files 48
Summary 49
Exam Preparation Tasks 49
End-of-Chapter Lab 51
Chapter 3 Essential File Management Tools 53
“Do I Know This Already?” Quiz 53
Foundation Topics 56
Working with the File System Hierarchy 56
Defining the File System Hierarchy 56
Understanding Mounts 57
Managing Files 61
Working with Wildcards 61
Managing and Working with Directories 61
Working with Absolute and Relative Pathnames 62
Listing Files and Directories 64
Copying Files and Directories 64
Moving Files and Directories 65
Deleting Files and Directories 66
Using Links 68
Understanding Hard Links 68
Understanding Symbolic Links 69
Creating Links 69
Removing Links 70
Working with Archives and Compressed Files 71
Managing Archives with tar 72
Creating Archives with tar 72
Monitoring and Extracting tar Files 73
Using Compression 74
Summary 75
Exam Preparation Tasks 76
End-of-Chapter Lab 77
Chapter 4 Working with Text Files 81
“Do I Know This Already?” Quiz 81
Foundation Topics 84
Using Common Text File–Related Tools 84
Doing More with less 84
Showing File Contents with cat 85
Displaying the First or Last Lines of a File with head and tail 86
Filtering Specific Columns with cut 87
Sorting File Contents and Output with sort 87
Counting Lines, Words, and Characters with wc 88
A Primer to Using Regular Expressions 89
Using Line Anchors 90
Using Escaping in Regular Expressions 91
Using Wildcards and Multipliers 91
Using Extended Regular Expressions 91
Using grep to Analyze Text 93
Working with Other Useful Text Processing Utilities 94
Summary 96
Exam Preparation Tasks 96
End-of-Chapter Lab 98
Chapter 5 Connecting to Red Hat Enterprise Linux 9 101
“Do I Know This Already?” Quiz 101
Foundation Topics 104
Working on Local Consoles 104
Logging In to a Local Console 104
Switching Between Terminals in a Graphical Environment 105
Working with Multiple Terminals in a Nongraphical Environment 107
Understanding Pseudo Terminal Devices 108
Booting, Rebooting, and Shutting Down Systems 109
Using SSH and Related Utilities 110
Accessing Remote Systems Using SSH 110
Using Graphical Applications in an SSH Environment 113
Securely Transferring Files Between Systems 114
Using scp to Securely Copy Files 114
Using sftp to Securely Transfer Files 115
Using rsync to Synchronize Files 115
Configuring Key-Based Authentication for SSH 116
Using Passphrases or Not? 116
Summary 117
Exam Preparation Tasks 118
End-of-Chapter Labs 119
Chapter 6 User and Group Management 121
“Do I Know This Already?” Quiz 121
Foundation Topics 124
Understanding Different User Types 124
Users on Linux 124
Working as Root 124
Using su 125
sudo 126
PolicyKit 127
Creating and Managing User Accounts 129
System Accounts and Normal Accounts 129
Creating Users 132
Modifying the Configuration Files 132
Using useradd 133
Home Directories 133
Default Shell 133
Managing User Properties 134
Configuration Files for User Management Defaults 134
Managing Password Properties 135
Creating a User Environment 135
Creating and Managing Group Accounts 137
Understanding Linux Groups 137
Creating Groups 137
Creating Groups with vigr 137
Using groupadd to Create Groups 138
Managing Group Properties 138
Summary 139
Exam Preparation Tasks 140
End-of-Chapter Labs 141
Chapter 7 Permissions Management 145
“Do I Know This Already?” Quiz 145
Foundation Topics 148
Managing File Ownership 148
Displaying Ownership 148
Changing User Ownership 149
Changing Group Ownership 150
Understanding Default Ownership 150
Managing Basic Permissions 151
Understanding Read, Write, and Execute Permissions 152
Applying Read, Write, and Execute Permissions 153
Managing Advanced Permissions 155
Understanding Advanced Permissions 155
Applying Advanced Permissions 157
Setting Default Permissions with umask 159
Working with User-Extended Attributes 160
Summary 162
Exam Preparation Tasks 162
End-of-Chapter Lab 164
Chapter 8 Configuring Networking 167
“Do I Know This Already?” Quiz 167
Foundation Topics 170
Networking Fundamentals 170
IP Addresses 170
IPv6 Addresses 171
IPv4 Network Masks 171
Binary Notation 172
MAC Addresses 173
Protocol and Ports 173
Managing Network Addresses and Interfaces 174
Validating Network Configuration 175
Validating Network Address Configuration 175
Validating Routing 178
Validating the Availability of Ports and Services 179
Managing Network Configuration with nmtui and nmcli 180
Required Permissions to Change Network Configuration 181
Configuring the Network with nmcli 182
Configuring the Network with nmtui 184
Working on Network Configuration Files 186
Setting Up Hostname and Name Resolution 187
Hostnames 187
DNS Name Resolution 189
Summary 191
Exam Preparation Tasks 191
End-of-Chapter Lab 193
Part II Operating Running Systems
Chapter 9 Managing Software 195
“Do I Know This Already?” Quiz 195
Foundation Topics 198
Managing Software Packages with dnf 198
Understanding the Role of Repositories 198
Registering Red Hat Enterprise Linux for Support 199
Managing Subscriptions 200
Specifying Which Repository to Use 200
Understanding Repository Security 203
Creating Your Own Repository 204
Using dnf 206
Using dnf to Find Software Packages 206
Getting More Information About Packages 208
Installing and Removing Software Packages 209
Showing Lists of Packages 211
Updating Packages 213
Working with dnf Package Groups 214
Using dnf History 216
Managing Package Modules 217
Understanding dnf Modules 218
Managing Modules 218
Managing Software Packages with rpm 221
Understanding RPM Filenames 222
Querying the RPM Database 222
Querying RPM Package Files 223
Using repoquery 224
Summary 226
Exam Preparation Tasks 226
End-of-Chapter Labs 227
Chapter 10 Managing Processes 231
“Do I Know This Already?” Quiz 231
Foundation Topics 234
Introduction to Process Management 234
Managing Shell Jobs 234
Running Jobs in the Foreground and Background 234
Managing Shell Jobs 235
Understanding Parent–Child Relations 237
Using Common Command-Line Tools for Process Management 237
Understanding Processes and Threads 238
Using ps to Get Process Information 239
Understanding Process Priorities 241
Exploring Relations Between Slices 241
Managing Process Priorities 242
Sending Signals to Processes with kill, killall, and pkill 243
Killing Zombies 245
Using top to Manage Processes 246
Using tuned to Optimize Performance 248
Summary 250
Exam Preparation Tasks 250
End-of-Chapter Lab 251
Chapter 11 Working with Systemd 253
“Do I Know This Already?” Quiz 253
Foundation Topics 256
Understanding Systemd 256
Understanding Systemd Unit Locations 256
Understanding Systemd Service Units 257
Understanding Systemd Mount Units 258
Understanding Systemd Socket Units 259
Understanding Systemd Target Units 260
Managing Units Through Systemd 261
Managing Dependencies 263
Managing Unit Options 265
Summary 267
Exam Preparation Tasks 267
End-of-Chapter Lab 268
Chapter 12 Scheduling Tasks 271
“Do I Know This Already?” Quiz 271
Foundation Topics 274
Understanding Task Scheduling Options in RHEL 274
Using Systemd Timers 274
Configuring cron to Automate Recurring Tasks 276
Managing the crond Service 276
Understanding cron Timing 278
Managing cron Configuration Files 278
Understanding the Purpose of anacron 281
Managing cron Security 282
Configuring at to Schedule Future Tasks 282
Summary 283
Exam Preparation Tasks 284
End-of-Chapter Lab 285
Chapter 13 Configuring Logging 287
“Do I Know This Already?” Quiz 287
Foundation Topics 290
Understanding System Logging 290
Understanding the Role of systemd-journald and rsyslogd 290
Reading Log Files 292
Understanding Log File Contents 293
Live Log File Monitoring 294
Using logger 294
Working with systemd-journald 295
Using journalctl to Find Events 295
Preserving the Systemd Journal 298
Configuring rsyslogd 300
Understanding rsyslogd Configuration Files 300
Understanding rsyslog.conf Sections 300
Understanding Facilities, Priorities, and Log Destinations 301
Rotating Log Files 304
Summary 306
Exam Preparation Tasks 306
End-of-Chapter Lab 308
Chapter 14 Managing Storage 311
“Do I Know This Already?” Quiz 311
Foundation Topics 314
Understanding MBR and GPT Partitions 314
Understanding the MBR Partitioning Scheme 314
Understanding the Need for GPT Partitioning 315
Understanding Storage Measurement Units 316
Managing Partitions and File Systems 317
Creating MBR Partitions with fdisk 318
Using Extended and Logical Partitions on MBR 320
Creating GPT Partitions with gdisk 322
Creating GPT Partitions with parted 327
Creating File Systems 328
Changing File System Properties 329
Managing Ext4 File System Properties 329
Managing XFS File System Properties 331
Adding Swap Partitions 332
Adding Swap Files 333
Mounting File Systems 333
Manually Mounting File Systems 334
Using Device Names, UUIDs, or Disk Labels 334
Automating File System Mounts Through /etc/fstab 335
Using Systemd Mounts 338
Summary 339
Exam Preparation Tasks 340
End-of-Chapter Lab 341
Chapter 15 Managing Advanced Storage 343
“Do I Know This Already?” Quiz 343
Foundation Topics 346
Understanding LVM 346
LVM Architecture 346
LVM Features 347
Creating LVM Logical Volumes 348
Creating the Physical Volumes 350
Creating the Volume Groups 353
Creating the Logical Volumes and File Systems 355
Understanding LVM Device Naming 355
Resizing LVM Logical Volumes 358
Resizing Volume Groups 358
Resizing Logical Volumes and File Systems 358
Reducing Volume Groups 360
Configuring Stratis 361
Understanding Stratis Architecture 362
Creating Stratis Storage 362
Managing Stratis 363
Summary 365
Exam Preparation Tasks 365
End-of-Chapter Labs 366
Part III Performing Advanced System Administration Tasks
Chapter 16 Basic Kernel Management 369
“Do I Know This Already?” Quiz 369
Foundation Topics 372
Understanding the Role of the Linux Kernel 372
Understanding the Use of Kernel Threads and Drivers 372
Analyzing What the Kernel Is Doing 373
Working with Kernel Modules 375
Understanding Hardware Initialization 376
Managing Kernel Modules 378
Checking Driver Availability for Hardware Devices 381
Managing Kernel Module Parameters 382
Upgrading the Linux Kernel 383
Summary 383
Exam Preparation Tasks 384
End-of-Chapter Lab 385
Chapter 17 Managing and Understanding the Boot Procedure 387
“Do I Know This Already?” Quiz 387
Foundation Topics 390
Managing Systemd Targets 390
Understanding Systemd Targets 390
Working with Targets 390
Understanding Target Units 391
Understanding Wants 392
Managing Systemd Targets 392
Isolating Targets 393
Setting the Default Target 396
Working with GRUB 2 396
Understanding GRUB 2 396
Understanding GRUB 2 Configuration Files 397
Modifying Default GRUB 2 Boot Options 398
Summary 399
Exam Preparation Tasks 399
End-of-Chapter Labs 401
Chapter 18 Essential Troubleshooting Skills 403
“Do I Know This Already?” Quiz 403
Foundation Topics 406
Understanding the RHEL 9 Boot Procedure 406
Passing Kernel Boot Arguments 408
Accessing the Boot Prompt 408
Starting a Troubleshooting Target 409
Using a Rescue Disk 410
Restoring System Access Using a Rescue Disk 411
Reinstalling GRUB Using a Rescue Disk 413
Re-creating the Initramfs Using a Rescue Disk 413
Fixing Common Issues 414
Reinstalling GRUB 2 414
Fixing the Initramfs 415
Recovering from File System Issues 415
Resetting the Root Password 416
Summary 417
Exam Preparation Tasks 417
End-of-Chapter Lab 419
Chapter 19 An Introduction to Automation with Bash Shell Scripting 421
“Do I Know This Already?” Quiz 421
Foundation Topics 424
Understanding Shell Scripting Core Elements 424
Using Variables and Input 426
Using Positional Parameters 426
Working with Variables 427
Using Conditional Loops 429
Working with if … then … else 430
Using || and && 431
Applying for 431
Understanding while and until 432
Understanding case 434
Bash Shell Script Debugging 435
Summary 435
Exam Preparation Tasks 436
End-of-Chapter Lab 437
Part IV Managing Network Services
Chapter 20 Configuring SSH 439
“Do I Know This Already?” Quiz 439
Foundation Topics 442
Hardening the SSH Server 442
Limiting Root Access 442
Configuring Alternative Ports 443
Modifying SELinux to Allow for Port Changes 443
Limiting User Access 444
Using Other Useful sshd Options 445
Session Options 446
Connection Keepalive Options 446
Configuring Key-Based Authentication with Passphrases 447
Summary 448
Exam Preparation Tasks 448
End-of-Chapter Lab 450
Chapter 21 Managing Apache HTTP Services 453
“Do I Know This Already?” Quiz 453
Foundation Topics 456
Configuring a Basic Apache Server 456
Installing the Required Software 456
Identifying the Main Configuration File 456
Creating Web Server Content 459
Understanding Apache Configuration Files 460
Creating Apache Virtual Hosts 462
Summary 464
Exam Preparation Tasks 464
End-of-Chapter Lab 466
Chapter 22 Managing SELinux 469
“Do I Know This Already?” Quiz 470
Foundation Topics 473
Understanding SELinux Working Modes 473
Understanding Context Settings and the Policy 477
Monitoring Current Context Labels 477
Setting Context Types 479
Finding the Context Type You Need 482
Restoring Default File Contexts 483
Managing Port Access 484
Using Boolean Settings to Modify SELinux Settings 485
Diagnosing and Addressing SELinux Policy Violations 487
Making SELinux Analyzing Easier 489
Summary 490
Exam Preparation Tasks 491
End-of-Chapter Lab 492
Chapter 23 Configuring a Firewall 495
“Do I Know This Already?” Quiz 495
Foundation Topics 498
Understanding Linux Firewalling 498
Understanding Previous Solutions 498
Understanding Firewalld 498
Understanding Firewalld Zones 499
Understanding Firewalld Services 500
Working with Firewalld 501
Summary 504
Exam Preparation Tasks 504
End-of-Chapter Lab 506
Chapter 24 Accessing Network Storage 509
“Do I Know This Already?” Quiz 509
Foundation Topics 512
Using NFS Services 512
Understanding NFS Security 512
RHEL NFS Versions 512
Setting Up NFS 513
Mounting the NFS Share 514
Mounting Remote File Systems Through fstab 515
Mounting NFS Shares Through fstab 515
Using Automount to Mount Remote File Systems 516
Understanding Automount 516
Defining Mounts in Automount 516
Configuring Automount for NFS 517
Using Wildcards in Automount 517
Summary 518
Exam Preparation Tasks 518
End-of-Chapter Lab 520
Chapter 25 Configuring Time Services 523
“Do I Know This Already?” Quiz 523
Foundation Topics 526
Understanding Local Time 526
Using Network Time Protocol 527
Managing Time on Red Hat Enterprise Linux 527
Using date 528
Using hwclock 528
Using timedatectl 529
Managing Time Zone Settings 531
Configuring Time Service Clients 533
Summary 534
Exam Preparation Tasks 535
End-of-Chapter Lab 536
Chapter 26 Managing Containers 539
“Do I Know This Already?” Quiz 539
Foundation Topics 542
Understanding Containers 542
Container Host Requirements 543
Containers on RHEL 9 544
Container Orchestration 545
Running a Container 545
Working with Container Images 550
Using Registries 550
Finding Images 552
Inspecting Images 553
Performing Image Housekeeping 556
Building Images from a Containerfile 556
Managing Containers 558
Managing Container Status 558
Running Commands in a Container 559
Managing Container Ports 561
Managing Container Environment Variables 562
Managing Container Storage 563
Running Containers as Systemd Services 566
Summary 568
Exam Preparation Tasks 569
End-of-Chapter Lab 570
Chapter 27 Final Preparation 573
General Tips 573
Verifying Your Readiness 573
Registering for the Exam 573
On Exam Day 574
During the Exam 575
The Nondisclosure Agreement 576
Chapter 28 Theoretical Pre-Assessment Exam 579
Part V RHCSA 9 Practice Exams
RHCSA Practice Exam A 581
RHCSA Practice Exam B 583
Appendix A: Answers to the “Do I Know This Already?” Quizzes and Review Questions 585
Appendix B: Red Hat RHCSA 9 Cert Guide: EX200 Exam Updates 617
Glossary 619

Online Elements:
RHCSA Practice Exam C
RHCSA Practice Exam D
Appendix C: Memory Tables
Appendix D: Memory Tables Answer Key
Appendix E: Study Planner
Glossary


9780138096274 TOC 3/24/2023