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  • About
    • About me
    • Legal
    • GNU Free Documentation License
    • Glossary
    • Bibliography
    • Decimal Naming and Prefixes
    • Contact
  • A Little History of Linux
    • The Unix and Linux Philosophy
      • Quotes
    • The Linux Philosophy for SysAdmins
      • Data Streams
      • Everything is a File – A Critical Concept
      • Linux Philosophy Saves the Day – Automate Everything!
      • The Linux Philosophy — Oregon State University
      • The real reason we use Linux
  • What is an Operating System
    • Definition of an Operating System
      • Genesis of the Operating System
      • Operating System Functions
  • DataBook for Linux Administrators
    • Fedora and Red Hat Documentation
    • Installation
      • Creating and Using Live Images
        • Creating a live Fedora USB image from the command line
        • Write Protect Errors Creating Bootable USB Thumb Drives
        • Error creating Live CD ISO Image
        • Creating USB Drive Install Image for Fedora
        • Making a Bootable USB Thumb Drive For Installation
      • Using the New Anaconda Installer in Fedora 18 and Above
      • Errors During Fedora Linux DVD Installation
      • Hardware Compatibility
        • BIOS Upgrades with FreeDOS
        • Testing hardware compatibility with Linux using Live USB memory sticks
        • nVidia vs ATI/Radeon Video
        • Video Hardware
        • Getting Linux to Run on Intel DG33FB Motherboard
        • Intel DP35DP Motherboard And Fedora
        • Beware of Foxconn Motherboards
      • Software RAID
        • Configuring Software RAID1 Arrays in Linux
        • Failing and Removing a Device From a RAID 1 Array in Linux
      • Default Partitioning and Disk Layout During Installation
      • Advanced Partitioning and Disk Layout During Installation
      • Kickstart
        • Complete Kickstart
      • Fedora 11 Installation Guide
      • Fedora 13 Installation Guide
      • Fedora 14 Installation Guide
      • Sample Linux Installation Procedures
        • Installing Fedora Linux 15 Through 17
        • Installing Fedora Linux 18
        • Fedora 15 through 18 Post Installation
        • Installing Fedora Linux 19
      • Post-Installation Problems
        • SSH and YUM don’t work after Fedora 10 Installation
    • Upgrades
      • Upgrade Fedora with dnf system-upgrade – Fedora 22 and above
      • Upgrades with fedup – not so much!
      • Upgrades with preupgrade
      • Upgrades not recommended with Fedora 18 through 22
      • Fedora 11 Upgrade Problems With YUM
      • Boot Fails After Upgrade from Fedora 10 to Fedora 11
      • Applications Won’t Start After Fedora 10 Upgrade
    • Migrating to Linux
      • Creating a Default KDE Desktop for New Accounts
      • Migrating Microsoft Contacts to Thunderbird
      • Importing Local Folders From Microsoft Mail into Thunderbird
    • Bootup and Linux startup
      • The Linux Boot Process
        • BIOS POST
        • GRUB
          • Configuring GRUB
          • Using the GRUB Menu to Alter the Boot Sequence
        • Kernel Boot Parameters
        • Kernel Initialization
        • GRUB2
          • Configuring GRUB2
      • Startup Using SystemV Init Scripts
        • Understanding Run Levels
        • init
        • Understanding /etc/inittab
        • rc.sysinit
        • rc
      • The startup process using systemd
        • Starting and Managing Linux Services Using systemd
      • Setting the host name
    • Filesystems
      • Anatomy of a Disk Drive
      • Disk Drive Types
      • The Linux Kernel and HDD Types
      • Introduction to Linux Filesystems
      • Linux Filesystem Hierarchical Standard
      • Understanding the /dev directory
      • The Linux Extended Filesystems
        • EXT2 Filesystem
        • The Linux EXT4 filesystem
      • Using hard and soft links in the Linux filesystem
      • Logical Volume Manager – LVM
        • LVM Structure
        • Creating a new Volume Group and Logical Volume
        • Resizing a Logical Volume in an LVM Filesystem
        • Changing the name of a Volume Group
      • Using the Loopback devices
      • File Permissions
      • Managing Cruft in tmp directories
    • Swap space on Linux Systems
      • Adding more swap space
    • The Command Line Interface (CLI)
      • Using Screen
      • Using Virtual Consoles
      • Tilix – Extreme Terminal Emulation
      • The GNU Core Utilities
      • Pipe Dreams
      • Fedora 16 crontab Problem
      • Setting vi Mode for Command Line Editing
    • System Tools
      • The /proc filesystem
      • Setting Colors in vim
      • Colors in Midnight Commander
      • The date Command
    • System Administration
      • Real SysAdmins don’t sudo
      • Using sudo to delegate
      • Everything is a File
      • Introducing regular expressions
      • About UDEV
      • Scheduling tasks with cron
      • Serial Console Usage
      • Performance Tuning
        • Removing kactivitymanagerd
        • KDE — How to disable Nepomuk, Strigi, Baloo and Akonadi
        • Removing ModemManager
      • When to reboot a Linux computer
      • Linux Standards and Best Practices
    • Software Updates
      • How to Disable PackageKit
    • Networking
      • BIND and Named – Name Services
        • Introduction to the Domain Name System (DNS)
        • Set up a DNS server using BIND
        • DNS secondary server does not update
        • DNS Problems in Fedora 12 and 13
      • Network Manager
        • Disable NetworkManager
      • Network Configuration
        • CIDR – Network notation and configuration
        • Introduction to Network Routing
        • Making your Linux Box Into a Router
        • Configuring Network Interface Controllers (NIC)
      • Networking Problems
        • Intel e1000e link speed only 100Mb rather than 1000Mb
        • Resetting Stale NFS Handles in Linux
      • Network Interface Card (NIC) name assignments
    • Printing
      • Printing Problems After Upgrade from Fedora 10 to 11
      • Printer Won’t Print After Going Into Sleep Mode
      • Printing With a Xerox WorkCenter Pro 128
      • Printing with the Dell V505 All-In-One Printer
      • Lexmark Printers Not Supported in Linux
      • USB Hardware Printing Problems
    • The X Window System
      • Installing System Fonts Using the Command Line
      • The Display Manager
      • xorg.conf Not Created in Fedora 14
    • Security
      • Generating passwords
      • Firewalls
        • New Firewall – firewalld
        • Reverting to IPTables from firewalld
        • Blocking Brute Force SSH Attacks
      • shred – Deleting Files Securely
      • Backups and Disaster Recovery
        • The Backup Plan
        • Using tar and ssh for backups
        • Using rsync for Backup
    • Scripting Languages
      • BASH Code to Determine Valid IP Addresses
      • The awk Language
    • Apache Web Server
      • Basic Apache Web Server Configuration
      • Configuring multiple web sites with Apache
      • Configuration changes in Apache 2.4
    • Email
      • Configuring the Alpine email client
      • Sorting Email – Using SpamAssassin, MimeDefang and Procmail
      • sendmail
        • SendMail Error Message: 553 5.1.8 … Domain of sender address … does not exist
        • Outbound Authentication for Sendmail
        • Forwarding Email from Hosts with no DNS Entries
        • Using port forwarding when ISP’s block port 25 for outbound email
      • Can’t connect on IMAP to receive email on mobile devices – Server busy error
    • Troubleshooting
      • The Five Steps of Problem Solving
        • Knowledge
        • Observation
        • Deduction
        • Action
        • Testing
      • Troubleshooting Example
      • Important First Steps in Solving Problems
      • Problem Determination Tools
        • Open source tools for monitoring your Linux system
        • Temperature monitoring tools to keep your Linux computer cool
        • top
        • Diagnosing CPU and memory related performance problems
        • Priorities, Nice Numbers and How to Use Them
      • Environmental Problems – EMI
        • EMI Sources
          • EMI – Radio and TV
          • EMI – Radar and Microwave
          • EMI – Static Electricity
          • EMI – Electrical Noise
          • EMI – Engines
          • EMI – Magnetic Fields
        • EMI Problems – Bothering your Neighbors
        • How to Minimize EMI Problems
      • Specific Problems
        • TigerVNC viewer blank
        • Cannot Login Using GUI
        • Horizontal Bar in Display
        • Xterm Windows Freeze Up in VNC Session
        • Fedora 10 – Network Only Works Outbound
    • Compiling the Kernel
      • Using Multiple Threads When Compiling the Kernel
    • Applications
      • ChurchInfo
        • ChurchInfo: Fatal Error: $_SESSION[‘sURLPath’] is empty
        • Installing ChurchInfo
        • ChurchInfo: Empty pages
      • WordPress
        • WordPress xmlrpc.php vulnerability
      • VirtualBox
        • VirtualBox VMs Very Slow
        • Installing VirtualBox Using the RPMFusion Repository
        • Sharing Virtual Machines on a Single VirtualBox Host
        • Making USB Work in VirtualBox Guests
      • Setting User Interface Fonts for Firefox and Thunderbird
    • Multimedia
      • Troubleshooting Audio Adapter Problems
  • Downloads
  • News and Reviews
    • VirtualBox – Free and Easy Virtualization
  • Humor
    • Blinkenlights
    • The Gospel of Tux (v1.0)
    • The ABC’s of Unix
    • The Perfect Programmer
  • Archives
    • Archived reviews
      • Fedora 21 – Major changes to installation options
    • DataBook for Linux Users
      • Introduction
        • Linux Distributions
      • Section: The Basics
        • Chapter — How Do I Get Started?
          • Turning the Computer On
          • Login to the Computer
          • Make KDE Your Default Desktop
          • Linux and Security
          • When You Are Finished Using the Computer
        • Chapter — Introduction to Graphical User Interfaces (GUI)
          • Using Multiple Desktops
          • Anatomy of a Window
        • Chapter — Using KDE 3.5
          • 1. Kool Desktop Environment
          • 2. The KDE Panel
            • 1. Anatomy of the KDE Panel
            • 2. Configuring the KDE Panel
          • 3. The KDE Menu
          • 5. Switching Users
          • 6. Configuring KDE
            • Changing the Look of KDE
              • 1. KDE Themes
              • 2. Changing the Background
              • 3. Choosing a Color Scheme
              • 4. Fonts
              • 5. Icons
              • 6. Launch Feedback
              • 7. Screen Saver
              • 8. Splash Screen
              • 9. Style
              • 10. Theme Manager
              • 11. Window Decorations
            • Changing How The Desktop Works
              • 1. Behavior
              • 2. Multiple Desktops
              • 3. Panels
              • 4. Task Bar
              • 5. Window Behavior
            • Peripherals
              • Mouse
            • What Happens to My Changes When I Upgrade?
            • Getting Back to the Defaults
        • Chapter — Using KDE 4
          • Introducing KDE 4
          • The KDE 4 Panel
            • Anatomy of the KDE 4 Panel
            • Configuring the KDE 4 Panel
          • The KDE 4 Menu
          • Switching Users
          • KDE4 Problem Solving
            • Reset KDE Wallet Password
      • Section: Managing Files
        • Computer Memory — RAM vs Disk Drives and Files
        • Searching for Files with KDE
        • Comparison of Common File Managers
        • Using the Dolphin File Manager
        • Using Midnight Commander
        • Using Konqueror
        • Associating Files with Application Programs
        • Using the Krusader file manager
        • Using the Standard KDE File Manager to Save Files
        • Extracting Zip Archives
      • Section: Internet Applications
        • Chapter — Email with Thunderbird
          • Setting Font Sizes for Message Text in Thunderbird
          • Multipurpose Internet Mail Extensions (MIME)
          • Opening Attachments Directly From Thunderbird
          • Saving Attachments and Photos
        • Chapter — Surfing the Internet With Firefox
          • Tabbed Browsing with Firefox
          • Viewing Embedded Documents and Videos with Firefox
          • Error: Firefox is already running
      • Chapter — Multimedia
        • Using K3B to Burn a CD or DVD
        • Choosing a Webcam for Linux
        • Basic Scanning with XSane
      • Chapter — Application Programs
        • GnuCash
        • LibréOffice
        • OpenOffice
          • Dealing with Word Document Formatting Problems
      • Chapter — Printing in Linux
      • Chapter — Problem Solving
        • Recovering from a Display Problem
    • DataBook for OS/2
      • Front Material
        • Notes About The Rebuild of the DataBook for OS/2 Warp
        • Forward
        • Warp Products Covered by the DataBook For OS/2
        • OS/2 Reference Books
      • Chapter 1 – What is an Operating System and why is it Important?
        • Computers and Technology In Today’s Business
          • Wasted Computing Power
          • Why Multitasking?
          • Multitasking in Windows 3.1
          • Multitasking in Windows 95
          • Multitasking in Windows NT
          • Multitasking in OS/2 Warp
          • Computer-Centric Strategies for Enhancing Productivity
          • SETI@Home – A Perfect Example of Multitasking
        • What is OS/2 Warp?
          • Introducing OS/2 Warp
          • Warp Features
          • Warp Server
          • OS/2 Awards
          • A Short History of OS/2
          • The Future of OS/2
        • Who Uses OS/2 Warp
          • When was the last time you used OS/2
          • Who uses Warp in North America
          • Who uses OS/2 Warp in Europe
          • Who uses OS/2 in Asia
          • Who uses OS/2 elsewhere
        • Introduction To Operating Systems
          • Defining an Operating System
          • Genesis of the Operating System
          • Operating System Features
          • OS/2 Warp from a Programmer’s Viewpoint
      • Chapter 02 – Inside OS/2 Warp
        • The OS/2 Kernel
        • OS/2 Multitasking
        • OS/2 Crash Protection
        • The Swap File
        • OS/2 Memory Management
        • Ring Protection mechanism
        • Dynamic Link Libraries – DLL
        • Symmetric MultiProcessing (SMP)

Firewalls

Up one level: Security
Previous: Generating passwords
Next: New Firewall – firewalld


This section of the DataBook for Linux Administrators contains information about the two firewalls used in Fedora.

  • IPTables
  • firewalld

Starting with Fedora 18, firewalld replaces the older IPTables firewall.

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Up one level: Security
Previous: Generating passwords
Next: New Firewall – firewalld


Book News

Be sure to check my personal web site for news of my books. My first book, “The Linux Philosophy for SysAdmins,” was published in 2018 by Apress.

My next project – a series of three books that make up a complete Linux self study course – “Using and Administering Linux – Zero to SysAdmin,” also from Apress, is due out in late 2019.

Random Quote

Adding more programmers to a late software project makes it later.

— Brook’s Law

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Newest Pages

  • Introducing regular expressions
    Note: This article is a slightly modified version of Chapter 6 from Volume 2 of [...]
    11-01-2019
  • Data Streams
    Author’s note: Much of the content in this article is excerpted -- with some [...]
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  • Scheduling tasks with cron
    so you don't have to stay up late Being a SysAdmin has its advantages but it [...]
    09-21-2019
  • Real SysAdmins don’t sudo
    I was just reading a very interesting article that contained some good informa [...]
    09-20-2019
  • The Linux Philosophy for SysAdmins
    Background The Unix Philosophy is an important part of what makes Unix uniqu [...]
    09-20-2019
  • Archived reviews
    09-18-2019
  • Using sudo to delegate
    I have recently written a short Bash program to copy some MP3 files from a USB [...]
    09-18-2019
  • About me
    Welcome to my technical blog where I write mostly technical articles and posts [...]
    09-17-2019
  • Archives
    This section contains older pages that should not be deleted for historical rea [...]
    08-13-2019
  • USB Hardware Printing Problems
    Usually printing with Linux is easy. Most USB printers are automatically config [...]
    08-13-2019

Admin Tools

  • 80 Linux Monitoring Tools for SysAdmins

Distributions

  • CentOS
  • DistroWatch
  • Fedora Project
  • Red Hat

Documentation

  • Fedora Documentation
  • LibreOffice Documentation
  • Red Hat Documentation
  • The job is not done until the documentation is complete

Enlightenment

  • Nine traits of the veteran Unix admin
  • Open Life: The Philosophy of Open Source
  • Open Sources : Voices from the Open Source Revolution
  • The Art of Unix Programming
  • The Tao of Open Source
  • The Tao of Programming
  • The Unix Power Classic

Filesystem

  • Filesystem Hierarchy Standard

History

  • Arnold Robbins home page
  • Unix pioneers reminisce

Linux

  • How to do fast, repeatable Linux installations
  • Linux monitoring tools to keep your hardware cool
  • My mom requests a Linux computer
  • Red Hat
  • RPMFusion Repositories
  • The Art of Unix Programming
  • The job is not done until the documentation is complete
  • The Tao of Programming
  • The Unix Power Classic
  • Why Linux is Better

Linux Boot

  • Linux Kernel Boot Process

My Articles

  • 8 Linux file managers to try
  • 9 reasons to use KDE
  • A comprehensive guide to Dolphin, a KDE file manager
  • A troubleshooting process for Linux problems
  • Complete Kickstart
  • Everything is a file
  • Get started with Midnight Commander, a Linux file manager
  • How I landed a job in open source
  • How the 9 major tenets of the Linux philosophy affect you
  • How to do fast, repeatable Linux installations
  • Human Interface Guidelines (HIG) for the Unix shell
  • Linux monitoring tools to keep your hardware cool
  • My mom requests a Linux computer
  • Solving City Problems the Open Source Way
  • Take control of your file systems with Konqueror
  • The impact of the Linux philosophy
  • The job is not done until the documentation is complete

Open Source

  • GnuCash Accounting Software
  • How the 9 major tenets of the Linux philosophy affect you
  • How to do fast, repeatable Linux installations
  • LibreOffice
  • OpenSource.com
  • Solving City Problems the Open Source Way
  • The impact of the Linux philosophy

OpenSource.com

  • How the 9 major tenets of the Linux philosophy affect you
  • How to do fast, repeatable Linux installations
  • Human Interface Guidelines (HIG) for the Unix shell
  • Linux monitoring tools to keep your hardware cool
  • My mom requests a Linux computer
  • Solving City Problems the Open Source Way
  • The impact of the Linux philosophy
  • The job is not done until the documentation is complete

Package Repositories

  • EPEL
  • RPMFusion Repositories

Software

  • FreeOpenSourceSoftware.org
  • GnuCash Accounting Software
  • LibreOffice

Unix

  • Arnold Robbins home page
  • Unix pioneers reminisce

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