David Clinton is a Linux server administrator who has worked with IT infrastructure in academic and enterprise environments. He has taught video courses for Amazon Web Services, as well as other technologies. He is a co-author of AWS Certified Solutions Architect Study Guide: Associate (SAA-C01) Exam and AWS Certified Cloud Practitioner Study Guide: Foundational (CLF-C01) Exam.

Christopher Negus is a senior open source technical writer at Amazon Web Services. He has written dozens of books on Linux, including Red Hat Linux Bible, Linux Troubleshooting Bible and Linux Toys.

Acknowledgments ix

Introduction xxix

Part I: Getting Started 1

Chapter 1: Starting with Linux 3

Understanding What Linux is 4

Understanding How Linux Differs from Other Operating Systems 6

Exploring Linux History 7

Free-flowing UNIX culture at Bell Labs 7

Commercial UNIX 9

Berkeley Software Distribution arrives 9

UNIX Laboratory and commercialization 10

GNU transitions UNIX to freedom 11

BSD loses some steam 13

Linus builds the missing piece 13

OSI open source definition 14

Understanding How Linux Distributions Emerged 16

Understanding Red Hat 17

Understanding Ubuntu and other Debian distributions 17

Finding Professional Opportunities with Linux Today 18

Understanding how companies make money with Linux 19

Summary 20

Chapter 2: Creating the Perfect Linux Desktop 21

Understanding Linux Desktop Technology 22

Starting with the GNOME 3 Desktop Live Image 24

Using the GNOME 3 Desktop 25

After the computer boots up 25

Navigating with the mouse 25

Navigating with the keyboard 30

Setting up the GNOME 3 desktop 31

Extending the GNOME 3 desktop 31

Using GNOME shell extensions 32

Using the GNOME Tweak Tool 33

Starting with desktop applications 33

Managing files and folders with Nautilus 33

Installing and managing additional software 35

Playing music with Rhythmbox 37

Stopping the GNOME 3 desktop 37

Using the Unity Graphical Shell with the GNOME Desktop 37

Using the Metacity window manager 38

Changing GNOME's appearance 40

Using the panels 40

Adding a drawer 41

Changing panel properties 41

Summary 42

Exercises 42

Part II: Becoming a Linux Power User 43

Chapter 3: Using the Shell 45

About Shells and Terminal Windows 46

Using the shell prompt 47

Using a Terminal window 48

Using virtual consoles 49

Choosing Your Shell 49

Running Commands 50

Understanding command syntax 51

Locating commands 53

Recalling Commands Using Command History 56

Command-line editing 56

Command-line completion 58

Command-line recall 59

Connecting and Expanding Commands 61

Piping between commands 62

Sequential commands 62

Background commands 63

Expanding commands 63

Expanding arithmetic expressions 63

Expanding variables 64

Using Shell Variables 64

Creating and using aliases 66

Exiting the shell 67

Creating Your Shell Environment 67

Configuring your shell 67

Setting your prompt 68

Adding environment variables 70

Getting Information about Commands 71

Summary 74

Exercises 74

Chapter 4: Moving Around the Filesystem 77

Using Basic Filesystem Commands 80

Using Metacharacters and Operators 82

Using fi le-matching metacharacters 82

Using fi le-redirection metacharacters 84

Using brace expansion characters 85

Listing Files and Directories 86

Understanding File Permissions and Ownership 90

Changing permissions with chmod (numbers) 91

Changing permissions with chmod (letters) 92

Setting default file permission with umask 93

Changing file ownership 93

Moving, Copying, and Removing Files 94

Summary 95

Exercises 96

Chapter 5: Working with Text Files 97

Editing Files with vim and vi 97

Starting with vi 99

Adding text 99

Moving around in the text 100

Deleting, copying, and changing text 101

Pasting (putting) text 102

Repeating commands 102

Exiting vi 102

Skipping around in the file 103

Searching for text 103

Using ex mode 104

Learning more about vi and vim 104

Finding Files 105

Using locate to find files by name 105

Searching for files with find 107

Finding files by name 108

Finding files by size 108

Finding files by user 109

Finding files by permission 109

Finding files by date and time 110

Using "not" and "or" when finding files 111

Finding files and executing commands 112

Searching in files with grep 113

Summary 115

Exercises 115

Chapter 6: Managing Running Processes 117

Understanding Processes 117

Listing Processes 118

Listing processes with ps 118

Listing and changing processes with top 120

Listing processes with System Monitor 122

Managing Background and Foreground Processes 124

Starting background processes 124

Using foreground and background commands 125

Killing and Renicing Processes 126

Killing processes with kill and killall 126

Using kill to signal processes by PID 127

Using killall to signal processes by name 128

Setting processor priority with nice and renice 128

Limiting Processes with cgroups 129

Summary 131

Exercises 131

Chapter 7: Writing Simple Shell Scripts 133

Understanding Shell Scripts 133

Executing and debugging shell scripts 134

Understanding shell variables 135

Special shell positional parameters 136

Reading in parameters 137

Parameter expansion in bash 137

Performing arithmetic in shell scripts 138

Using programming constructs in shell scripts 139

The "if then" statements 139

The case command 142

The "for do" loop 143

The "while do" and "until do" loops 144

Trying some useful text manipulation programs 145

The global regular expression print 145

Remove sections of lines of text (cut) 145

Translate or delete characters (tr) 146

The stream editor (sed) 146

Using simple shell scripts 147

Telephone list 147

Backup script 148

Summary 149

Exercises 149

Part III: Becoming a Linux System Administrator 151

Chapter 8: Learning System Administration 153

Understanding System Administration 153

Using Graphical Administration Tools 155

Using Cockpit browser-based administration 155

Using other browser-based admin tools 157

Invoking Administration Privileges 158

Becoming root from the shell 158

Gaining temporary admin access with sudo 159

Exploring Administrative Commands, Configuration Files, and Log Files 161

Administrative commands 161

Administrative configuration files 162

Administrative log files and systemd journal 165

Using journalctl to view the systemd journal 165

Managing log messages with rsyslogd 166

Using Other Administrative Accounts 167

Checking and Configuring Hardware 167

Checking your hardware 168

Managing removable hardware 171

Working with loadable modules 172

Listing loaded modules 172

Loading modules 173

Removing modules 174

Summary 174

Exercises 175

Chapter 9: Installing Linux 177

Choosing a Computer 178

Installing Ubuntu Desktop 180

Installing Ubuntu Server 185

Understanding Cloud-Based Installations 188

Installing Linux in the Enterprise 189

Exploring Common Installation Topics 189

Upgrading or installing from scratch 189

Dual booting 190

Installing Linux to run virtually 191

Using installation boot options 192

Boot options for disabling features 192

Boot options for video problems 193

Boot options for special installation types 193

Using specialized storage 194

Partitioning hard drives 195

Understanding different partition types 196

Tips for creating partitions 196

Using the GRUB 2 boot loader 198

Summary 199

Exercises 199

Chapter 10: Getting and Managing Software 201

Managing Software on the Desktop 201

Going Beyond the Software Window 203

Understanding Linux Software Packaging 204

Working with Debian Packaging 205

APT basics 205

Working with APT repositories 209

Working with dpkg 211

Summary 214

Exercises 214

Chapter 11: Managing User Accounts 215

Creating User Accounts 215

Adding users with adduser 218

Setting user defaults 220

Modifying users with usermod 222

Deleting users with deluser 223

Understanding Group Accounts 223

Using group accounts 224

Creating group accounts 225

Managing Users in the Enterprise 225

Setting permissions with Access Control Lists 226

Setting ACLs with setfacl 227

Setting default ACLs 228

Enabling ACLs 229

Adding directories for users to collaborate 231

Creating group collaboration directories (set GID bit) 231

Creating restricted deletion directories (sticky bit) 233

Centralizing User Accounts 233

Summary 234

Exercises 234

Chapter 12: Managing Disks and Filesystems 237

Understanding Disk Storage 237

Partitioning Hard Disks 239

Understanding partition tables 239

Viewing disk partitions 240

Creating a single-partition disk 241

Creating a multiple-partition disk 245

Using Logical Volume Manager Partitions 249

Checking an existing LVM 249

Creating LVM logical volumes 252

Growing LVM logical volumes 254

Mounting Filesystems 254

Supported filesystems 255

Enabling swap areas 257

Disabling swap area 258

Using the fstab file to define mountable filesystems 258

Using the mount command to mount filesystems 261

Mounting a disk image in loopback 262

Using the umount command 262

Using the mkfs Command to Create a Filesystem 263

Managing Storage with Cockpit 264

Summary 265

Exercises 266

Part IV: Becoming a Linux Server Administrator 267

Chapter 13: Understanding Server Administration 269

Getting Started with Server Administration 270

Step 1: Install the server 270

Step 2: Configure the server 272

Using configuration files 272

Checking the default configuration 272

Step 3: Start the server 272

Step 4: Secure the server 274

Password protection 274

Firewalls 274

TCP Wrappers 274

AppArmor 275

Security settings in configuration files 275

Step 5: Monitor the server 275

Configure logging 275

Run system activity reports 276

Watch activity live with Cockpit 276

Keep system software up to date 277

Check the filesystem for signs of crackers 277

Checking and Setting Servers 277

Managing Remote Access with the Secure Shell Service 277

Starting the openssh-server service 278

Using SSH client tools 278

Using ssh for remote login 279

Using SSH for remote execution 280

Copying files between systems with scp and rsync 281

Interactive copying with sftp 284

Using key-based (passwordless) authentication 285

Configuring System Logging 286

Enabling system logging with rsyslog 287

Understanding the rsyslog.conf file 287

Understanding log messages 289

Setting up and using a loghost with rsyslogd 289

Watching logs with logwatch 290

Checking System Resources with sar 291

Checking System Space 293

Displaying system space with df 293

Checking disk...