CYAN YELLOW MAGENTA BLACK BOOKS FOR PROFESSIONALS BY PROFESSIONALS® THE EXPERT’s VOICE® IN LINUX Companion eBook Available Foundations of CentOS Linux: Foundations of CentOS Linux Ryan Baclit Enterprise Linux On the Cheap Dear Reader, I’ve been using Linux for years for software development, for personal enter- tainment, and to create servers to be deployed on the network. But when asked on which distribution I always use when creating and deploying network serv- ers, I always say CentOS. With CentOS, I have all the tools that I need to do tasks with Linux, from command-line shell scripting to graphical systems adminis- Chivas Sicam tration with virtualization. The book you are holding now contains expert advice that will help you learn Linux administration with the CentOS distribution. You will be able to Foundations of write shell scripts, schedule automated tasks and use the GNOME desktop. For network servers, you will learn how to properly install and configure file sharing and print servers, combine servers with directory services for unified authentication, and use virtualization to save on hardware costs. With this book, you have a concrete starting guide to learning Linux with CentOS. You will spend less time asking questions and more time to build- ing whatever you need with CentOS as you learn about it with this book. If Peter Membrey you have plans of becoming an RHCE (Red Hat Certified Engineer), what you CentOS Linux have learned here will give you a boost in studying review materials for the RHCE exam. I hope that you will enjoy learning Linux with CentOS and use it to create masterpiece servers with this book. Enterprise Linux On the Cheap Ryan Baclit John Newbigin THE APRESS ROADMAP Pro Linux System A truly free enterprise alternative Administration Beginning the Linux to Red Hat Enterprise Linux Command Line Pro Ubuntu Server Companion eBook Foundations of CentOS Linux Beginning Ubuntu Linux, The Definitive 4th edition Guide to SUSE Beginning Ubuntu Linux Enterprise Server LTS Server Administration The Definitive Guide Beginning SUSE Linux See last page for details to CentOS on $10 eBook version Baclit )3". Sicam Ryan Baclit, Chivas Sicam, Membrey Peter Membrey, and John Newbigin US $42.99 Newbigin Shelve in Linux User level: Beginning www.it-ebooks.info this print for content only—size & color not accurate trim = 7.5" x 9.25" spine = 0.000" 000 page count www.it-ebooks.info Foundations of CentOS Linux Enterprise Linux On the Cheap ■ ■ ■ Ryan Baclit, Chivas Sicam, Peter Membrey, and John Newbigin www.it-ebooks.info Foundations of CentOS Linux: Enterprise Linux On the Cheap Copyright © 2009 by Ryan Baclit, Chivas Sicam, Peter Membrey, and John Newbigin All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. The Evolution Mail Client logo is a copyright of Evolution project and was printed with permission. ISBN-13 (pbk): 978-1-4302-1964-4 ISBN-13 (electronic): 978-1-4302-1965-1 Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1 Trademarked names may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, we use the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. President and Publisher: Paul Manning Lead Editor: Frank Pohlmann Technical Reviewers: Peter Membrey and Ann Tan-Pohlmann Editorial Board: Clay Andres, Steve Anglin, Mark Beckner, Ewan Buckingham, Tony Campbell, Gary Cornell, Jonathan Gennick, Michelle Lowman, Matthew Moodie, Jeffrey Pepper, Frank Pohlmann, Ben Renow-Clarke, Dominic Shakeshaft, Matt Wade, Tom Welsh Coordinating Editor: Debra Kelly Copy Editors: James A. Compton, Heather Lang, Patrick Meader, and Sharon Terdeman Compositor: Bob Cooper Indexer: BIM Indexing and e-Services Artist: April Milne Cover Designer: Anna Ishchenko Distributed to the book trade worldwide by Springer-Verlag New York, Inc., 233 Spring Street, 6th Floor, New York, NY 10013. Phone 1-800-SPRINGER, fax 201-348-4505, e-mail [email protected], or visit http://www.springeronline.com. For information on translations, please e-mail [email protected], or visit http://www.apress.com. Apress and friends of ED books may be purchased in bulk for academic, corporate, or promotional use. eBook versions and licenses are also available for most titles. For more information, reference our Special Bulk Sales—eBook Licensing web page at http://www.apress.com/info/bulksales. The information in this book is distributed on an “as is” basis, without warranty. Although every precaution has been taken in the preparation of this work, neither the author(s) nor Apress shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in this work. The source code for this book is available to readers at http://www.apress.com. ii www.it-ebooks.info I dedicate this book to all current and future users of Linux. —Ryan Baclit To Anna. May all your dreams come true. —Chivas Sicam For my granddad, Bill “Pappy” Membrey. Without his unwavering support and guidance (not to mention patience), I would not be where I am today. —Peter Membrey To my fiancée, Jenna. —John Newbigin www.it-ebooks.info Contents at a Glance ■About the Authors ................................................................................................... xvii ■About the Technical Reviewer .................................................................................. xx ■Acknowledgments ................................................................................................... xxi ■Introduction ............................................................................................................ xxii ■Chapter 1: Installation ................................................................................................ 1 ■Chapter 2: BASH ....................................................................................................... 31 ■Chapter 3: Client/Host Configuration ........................................................................ 55 ■Chapter 4: Data Storage Management ...................................................................... 71 ■Chapter 5: User Management ................................................................................... 87 ■Chapter 6: X Window System ................................................................................. 105 ■Chapter 7: Package Management .......................................................................... 133 ■Chapter 8: Basic Linux Security ............................................................................. 153 ■Chapter 10: Network Security ................................................................................ 203 ■Chapter 11: Network Services ................................................................................ 227 ■Chapter 12: Open Source Databases ...................................................................... 261 ■Chapter 13: Linux Web Services ............................................................................. 289 ■Chapter 14: File Sharing Services .......................................................................... 313 ■Chapter 15: Linux Mail Servers .............................................................................. 335 ■Chapter 16: Directory Services ............................................................................... 373 ■Chapter 17: The Linux Kernel ................................................................................. 415 ■Chapter 18: Linux Virtualization ............................................................................. 435 ■Chapter 19: Linux Troubleshooting ......................................................................... 457 ■Index ....................................................................................................................... 471 iv www.it-ebooks.info ■ CONTENTS Contents ■About the Authors ................................................................................................... xvii ■About the Technical Reviewer .................................................................................. xx ■Acknowledgments ................................................................................................... xxi ■Introduction ............................................................................................................ xxii ■Chapter 1: Installation ................................................................................................ 1 Preinstallation Steps ......................................................................................................................................... 1 Installation ......................................................................................................................................................... 3 Troubleshooting ............................................................................................................................................... 29 Summary ......................................................................................................................................................... 30 ■Chapter 2: BASH