Linux System Administration

Marcel Gagné is best known as author of the Linux Journal's "Cooking with Linux" series, which has earned the magazine's Readers' Choice award for favorite column four years in a row, and as the regular "Linux Guy" on G4/TechTV Canada. His books include Moving to the Linux Business Desktop and Linux Administration: A User's Guide (both from Addison-Wesley.) He is one of the Linux world's most familiar and respected voices.

Acknowledgments.


1. Introduction.


What Is Linux?



Why Linux?



The System Administrator's Job.



About This Book.



The Command Line Rules!



GUIs Rule!



Flexibility.



Is There Anything You Can't Do with Linux?



Regrets, I've Had a Few....



Resources.



2. Linux versus Linux versus UNIX.


The UNIX Question.



The Windows Question



A Question of Distribution.



So Which Linux Distribution Should You Choose?



Red Hat Linux.



SuSE.



Caldera.



Mandrake.



Slackware.



Debian.



Turbolinux.



Getting Linux.



Getting Others to Try Linux.



Sharing Space with Windows.



How about No Disk Space At All?



A Changing Landscape.



Resources.



3. Help (and the Truth) Is Out There.


Documentation and Man Pages



What If You Don't Know the Command Name?



Show Me the PATH, man!



Graphical Man Pages.



info (the Command, That Is).



HOWTOs and Distributed DOCs



The Linux Documentation Project



Linux User Groups.



Usenet News.



Resources.



4. Linux System Installation.


Getting Ready for Your Installation.



Hardware Considerations.



Passing Boot Options



Dual Booting.



The 12 (13, 14, 15...) Steps to Any Installation.



Step 1: Booting.



Step 2: Selecting the Installation Type.



Step 3: Selecting a Language (Parlez-vous Francais?).



Step 4: Choosing a Keyboard Type.



Step 5: Selecting Your Mouse.



Step 6: Selecting a Time Zone.



Step 7: Creating a Partition



Step 8: Formatting the Partitions.



Step 9: To LILO or Not to LILO.



Step 10: Choosing and Installing Software Packages.



Step 11: Configuring the Network.



Step 12: Identifying Yourself.



Step 13: The Dreaded X Window Configuration.



Step 14: The Boot Disk Question.



The (Emergency) Boot Disk.



Starting Linux.



Shutting Down Linux.



Resources.



5. Taking Command of Linux.


Linux Commands: Love at First Sight.



Working with Files.



File Naming Conventions.



Listing Files with Emotion!



File Permissions: A First Look



Making Your Life Easier with alias



Standard Input and Standard Output



Piping



tee: A Very Special Pipe.



STDERR



The Road to Nowhere



Linux Commands: Working with Directories.



There's No Place Like $HOME



More on File Permissions



User and Group Ownership.



Who Can Do What?



Who Was That Masked User?



The setuid Bit



File Attributes



Finding Anything



grep’ping for Dollars (or Anything Else for That Matter) and Piping.



Processes.



Forests and Trees.



Interrupting, Suspending, and Restarting Processes.



Killing Processes.



“I Am vi, the Great and Powerful”



:q, :w, :wq, and ZZ



Recovering a VIM Session



Power vi: Start-up Options.



Pico: A kinder, gentler editor.



Emacs



Resources.



6. Daemons and Runlevels.


Daemons and Other Not-So-Scary Things.



The inittab File.



The rc.local File and Runlevels.



Switching between Runlevels



The chkconfig Command.



Runlevels the Graphical Way.



The (Not) Last Word.



Resources.



7. Users and Groups.


Living in a Multiuser World.



When Not to Use the root User.



Managing Users



Managing Groups



Adding Groups.



Modifying Groups.



Removing Groups.



Adding Users



About Home Directories.



Group Participation.



E-mail-Only Accounts



Yet More User-Creation Controls.



Modifying a User Account.



Deleting a User Account



Checking the Password File



User and Group Administration the GUI Way.



Choosing Good Passwords



How Crackers Crack Your Passwords.



Choosing Better Passwords.



What Next?



I Logged In from Where?



How Not to Be a “Sucker”.



Resources.



8. Disks and File Systems.


Everything Is a File.



Understanding Your File Systems.



The File System Tree.



The Root File System (aka /, or Slash).



The /usr File System.



The /var File System



The /tmp File System



The /proc File System



The /lost+found File System.



fsck: The File System Check and Repair Tool.



Bad Superblock?



How Much Space Have I Got Again?



What's This about Inodes?



Mounting and Unmounting File Systems.



Creating File Systems.



Using the New File System.



Working with Quotas



Getting Ready for Quotas.



Turning Quotas On and Off



Setting Limits.



Back to Grace



Letting the Users Know.



Resources.



9. X and the Graphical Desktop.


It's Just Window Dressing, Right?



Graphical Login Managers



Working without a Graphical Login Manager.



The World beneath the Surface.



The xinitrc File.



The .xserverrc File



The Xresources File



Specifying Resources on the Command Line.



Look, Ma! I Can Run Multiple Desktops!



Backing Up and Restoring the Desktop



Running X Applications Remotely



Choosing a Window Manager



The Tab Window Manager (twm).



Window Maker.



KDE.



GNOME.



Qvwm.



Tweaking X and Dealing with Problems.



Key Mapping.



Tuning Video Modes with xvidtune.



The “Messed Up” X Session.



Screen Captures



Resources



10. Dialing Up to the Internet with PPP.


The Basics.



What You Need from Your ISP.



Where the Information Goes



The Graphical Alternative.



Automagic PPP Connections.



eznet.



wvdial.



Resources.



11. Finding, Building, and Installing Software.


Finding Software and Software Review Sites.



Freshmeat.



TUCOWS Linux.



SourceForge.



Rpmfind



Ibiblio.org.



Installing and Building Software.



Compiling from Source.



Step 1: Unpacking the Archive.



Step 2: Building Your Programs.



Downloading and Installing Perl Modules.



Package Managers.



Updating or Installing Packages on a Debian System.



Great, but Can You Tell Me What Is Already There?



Finding Out a Package's Current Release Level



What Is That Strange File?



Using apt-get to Install or Update Software.



Educating apt-get.



Graphical Alternatives.



Red Hat Package Manager.



Installing an RPM Package.



Upgrading an RPM Package.



Uninstalling an RPM Package.



Everything You Ever Wanted to Know about an RPM Package, but Were Afraid to Ask.



RPM: The Graphical Alternatives.



installpkg: Slackware's Lonely Child.



Resources.



12. Kernel Building and Renovation.


What Is This Kernel, Anyhow?



When Should I Rebuild My Kernel?



Downloading and Building a New Kernel.



Automatic Build and Install



What about the 2.4 Kernel?



Resources.



13. Printers and Printing.


Selecting Printers for Linux (and a Note about “WinPrinters”)



How Printing Works.



Filters.



HP JetDirect Adaptors.



Printer Job Control.



Printing Anything to Any Printer.



Tying It Up: Advanced Filters with Ghostscript.



Why PostScript?



A Few PostScript Tricks.



Alternative Print Systems.



PDQ.



CUPS.



Miscellaneous Tips and Tricks.



Resources.



14. Scripting and Scripting Languages.


Shells As Far As the Eye Can See.



It's Commands All the Way Down.



Passing Parameters.



A First Look at Variables.



More on Variables



Special Characters.



Really Programming the Shell.



Specifying the Shell.



Perl.



Perl in Action: A Script for Monitoring Disk Space.



Other Languages Worthy of Consideration.



Resources.



15. Simplified Administration through Automation.


Constructive Laziness.



cron: Punching Linux's Clock.



Testing Your Job.



Editing the crontab.



Could I See an Example?



Running Jobs with at



A Question of Permissions.



Other Tools for Automation.



Automatic Downloads: ncftp.



Automatic Web Fetch: wget.



Scripting for Interactive Sessions: expect.



Automating Interactive Automation.



Resources.



16. Devices, Devices, and More Devices.


Creating Device Definitions.



Major Minor



SCSI versus IDE



Why Choose One over the Other?



CD-ROMs and CD-RWs



The Graphical Way to Burn



Scanners



Back Ends.



Front Ends.



XSane



Tape Drives.



Other Tape Formats.



Miscellaneous Devices.



Resources.



17. Backups and Restores.


The Need for Backups



Basic Tools in Every Linux System.



Using cpio.



Working with tar



Backing Up Windows Workstations.



Selecting a Backup Medium.



Backing Up with dump



Restoring with (You Guessed It) restore.



Identity Backups.



Backing Up to a CD-RW



Backups the Graphical Way.



Taper: A Text-Based Backup Utility.



Kdat: Graphical and Free



Commercial Solutions.



BRU



Arkeia



Other Considerations.



Final Words



Resources.



18. Network Administration.


The Light-Speed Introduction to TCP/IP (Act 18, Scene 1).



Protocols and Suites.



Services and Ports



IP Addresses, Networks, and Subnets, Oh My!



What Are Domains?



IP Addresses and Networks



Subnets, Netmasks, and Broadcast Addresses.



Intermezzo



Setting Up Your PC Network (Act 18, Scene 2).



Drivers



Setting the IP Address.



Routing



Using netstat



Domain Name Services (Act 18, Scene 3).



The /etc/hosts File



Will the Real DNS Please Stand Up.



Setting Up Your Own Name Server.



Defining Your Domain



The /etc/named.conf File.



Listing of /etc/named.conf.



Zones



Your Own Zone File



And Now the Reverse DNS Zone.



Does It Work?



What's All This about “Lame Servers”?



Who Gets to See the Information?



DNS Wrap-up



File Sharing Under Linux (Act 18, Scene 4).



Network File System.



How Does NFS Work?



Making a Remote File System Available.



Mounting an NFS Partition



Specifying Mounts with /etc/fstab



Simplifying Network Mounts with Linux autofs.



Network Information Service (Act 18, Scene 5).



Configuring the NIS Master Server.



Configuring the NIS Client.



The /etc/nsswitch.conf File.



Miscellaneous Network Tricks: Time Synchronization.



rdate.



NTP.



Wait! What about the GUIs?



Resources.



19. Tools, Tools, and More Tools.


The Web Browser Angle.



Linuxconf.



Webmin



Graphical Administration Tools.



Tiny but Powerful Tools.



Go-Anywhere Linux



tomsrtbt.



Trinux.



The Tiny Conclusion.



There's No Control Like Remote Control.



Resources.



20. Proof of Concept, Part 1.


Of Web Servers and Intranets



Building Your Own Corporate Portal.



Building Apache from Source.



Basic Apache Configuration.



Common Changes



The Basics of Web-Connected Databases.



An Introduction to PostgreSQL.



Perl DBI and DBD for Database Access.



Downloading and Installing the Modules.



The CGI Back End



The Face of the Intranet



Protecting Certain Pages.



Resources



21. Proof of Concept, Part 2.


The Connected Office, Linux Style



What to Look for in an ISP.



Setting Up Your ISP Dial-up Connection with diald.



Automatic Remote Mail Pickup with fetchmail



IP Forwarding and Masquerading.



DNS Revisited.



Putting It All Together.



Basic Firewall Services.



Setting Up the Mail Server with Linux.



Defining the Network.



The Components



Setting Up the POP3 Server.



Setting Up sendmail.



Stopping and Restarting sendmail.



Your DNS Setup.



Setting Up Users and Aliases.



Setting Up Your Client MUAs.



Let’s Send Some Mail



Not-So-Stupid sendmail Tricks



The Multiple Domain, Similar Address Dilemma.



The Multidrop Domain.



Stop the Spam!



Resources.



22. Integrating Windows with Linux.


An Introduction to Samba.



Getting and Building Samba.



A Note on Passwords.



Configuring the Server.



The PC Side



Printing with Samba



Printing from the Windows Client.



The GUI Way to Administer Samba.



Backing Up Windows Workstations.



Running Windows on Linux.



Wine



VMware



Win4Lin.



Resources.



23. System Logs and Accounting.


Your System Logs.



Looking at Your Log Files.



What the Names Mean



Cleaning Up and What the Numbers Mean.



syslogd: The Master Logger.



Back to the logger Program.



Automating the Log-Checking Process.



Logcheck.



Web Site Log Analysis.



Analog



The Webalizer.



Resources.



24. Secure Computing.


A Brief History of Encryption.



Personal Encryption



An Introduction to the Secure Shell.



What Are Your Options?



OpenSSH.



Secure Sockets Layer.



OpenSSH (Right Back Where You Started).



Secure File Transfers.



PGP and GnuPG.



Graphical Front Ends to GnuPG.



Building Trust Relationships.



Encrypting Electronic Mail.



Building a Secure Web Server.



Building the SSL-Enabled Apache Server.



Resources.



25. Security: The Battle for Your System.


What Is a “Script Kiddie”?



The Basics: Your TCP Wrappers.



What Your TCP Wrapper Is Telling You.



“Hey, My Logs Have Nothing in Them!”



Detecting the Cracker.



The Cracker's Not-So-Invisible Footsteps.



More Thoughts If You Have Been Cracked.



Port Scanners, Sniffers, and the Cracker's Tools.



Sniffers.



PortSentry: Active Intrusion Detection and Response.



ipchains and Firewalls.



Quick and Easy Firewall Solutions.



Locating the Cracker and Reporting Him or Her.



Keeping Up-to-Date.



Resources.



26. Performance Monitoring and Tuning.


The Search for the Holy Grail.



Monitoring and Analyzing Performance.



The uptime Command.



The top Command



Graphical tops.



The free Command



Working with vmstat



What about Good Ol' ps?



Performance Enhancing Tweaks.



/proc Revisited.



File System Tweaks.



Improving Disk Drive Performance.



Do-It-Yourself Benchmarks.



Resources.



Appendix A: The All-Linux Office?


Appendix B: The GNU General Public License.


Index. 0201719347T09242001