Unix system administration a beginners guide

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TE AM

UNIX System Administration:

A Beginner’s Guide

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UNIX System Administration:

A Beginner’s Guide

Steve Maxwell

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About the Author

Steve Maxwell has been actively involved with UNIX and computer networking for the last 20 years He has worked for a number of companies, institutions, and organizations in a variety of capacities that have included network design, software development, and training Recently, Steve decided that it was time

to join another start-up company, and he now works at FineGround Networks, Inc., where he is responsible for ensuring that the company delivers quality software products Steve welcomes your feedback on any aspect of this book—

please send comments, questions, and suggestions to sjmaxwell@worldnet.att.net.

About the Technical Reviewers

John Tiso is a senior consultant for NIS, a Boston-based integrator of Sun Microsystems and Cisco Systems He has a B.S degree from Adelphi University and is certified in UNIX from HP, Sun, and IBM John is also a Cisco CCIE (CCIE #5162), MCSE, and MCNE He has published papers in several leading

technical journals, such as Element K and SysAdmin, and has served as a technical editor for a variety of books John can be reached at johnt@jtiso.com.

Jim Minatel is a freelance writer and editor with more than 13 years of publishing experience in mathematics, statistics, and computing He has authored and co-authored several books about the Internet and World Wide Web in the early Netscape era, and most recently served as Editor in Chief for two magazines for networking professionals and IT managers He holds undergraduate degrees in mathematics and physics, and an M.S in mathematics

ACKNOWLEDGMENTS xvii

INTRODUCTION xix

1 Introduction to UNIX 1

1 Uncover the History of the UNIX System 2

2 Explore the Elements of a Computer System 3

3 Show the UNIX Timeline 7

AT&T Invents UNIX 7

BSD Is Born 8

The System V Releases 8

AT&T/Sun Deal 9

The Internet Worm 9

OSF/1 9

Mach 10

Linux Is Introduced 10

Red Hat 10

Versions of UNIX Today 10

Why UNIX Is Popular 11

Modular UNIX 15

The Kernel 15

4 Discover the Roles of the UNIX System Administrator 18

Support the Network 19

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viii UNIX System Administration: A Beginner’s Guide

Handle Peripherals 19

Manage System Upgrades 20

Actively Monitor System Security 20

Maintain System Accounts 21

Advance Your Knowledge 21

Teacher 22

Politician 22

Parent 23

Police Officer 23

Friend 24

Mastery Check 25

2 Basic UNIX Commands 27

1 Explore the UNIX Shell 28

2 Investigate Basic UNIX Commands 31

cat 34

date 35

hostname 37

find 38

ls 42

strings 49

ps 52

uname 59

Project 2-1 62

Mastery Check 63

3 Using System Administration Tools 65

1 Managing Solaris Using Admintool 67

Add a New User 67

UNIX Account Example 72

Modifying a User 73

Deleting a User 74

Adding a New Group 76

Modifying a Group 79

Deleting a Group 79

2 Manage Linux Accounts with Userconf . 80

Add a New User 80

Modifying a User 86

Delete an Existing User 88

Adding a New Group 90

3 Manage HP-UX Using SAM 92

Add a New User 94

Modifying a User 98

Delete an Existing User 99

Contents ix

Adding a New Group 101

Deleting an Existing Group 103

4 Set Up Better Account Security 105

Expiring a Password Using Admintool 106

Expiring a Password Using Userconf 106

Expiring a Password Using SAM 107

Regular Password Changes Using Admintool 109

Regular Password Changes Using Userconf 110

Turning Off an Account Using Admintool 111

Turning Off an Account Using Userconf 113

Automatic Account Expiration Using Userconf 114

Mastery Check 116

4 Software Package Management Tools 117

1 Discover Solaris Package Tools 119

pkginfo 119

pkgadd 123

pkgrm 124

2 Discover HP-UX Package Tools 126

swlist 126

swinstall 130

Project 4-1 130

swremove 133

Project 4-2 133

3 Discover Linux Package Tools 136

Project 4-3 137

Mastery Check 139

5 Maintaining UNIX Users 141

1 Discover the /etc/passwd File 142

2 Discover the /etc/group File 146

3 Discover the /etc/shadow File 149

4 Explore UNIX Account Tools 152

passwd 153

pwck 156

grpck 159

useradd 159

userdel 161

usermod 162

groupadd 163

groupdel 164

groupmod 164

logins 164

vipw 166