Debian Administration Training Course

Debian Distribution

What is Debian?

• Choosing the appropriate Debian version
• Accessing Debian support and assistance
• Engaging with the Debian community

Console fundamentals

• Understanding the shell prompt
• Utilizing the shell prompt within the X environment
• Managing the root account and root shell prompt (using su, sudo, and executing programs as root under X)
• Employing GUI system administration tools
• Navigating virtual consoles
• Exiting the command prompt
• Shutting down the system
• Restoring a functional console
• Recommended packages for beginners
• Setting up an additional user account
• Configuring sudo

Understanding the filesystem

• Filesystem permissions
• Controlling permissions for newly created files via umask
• Managing permissions for user groups
• Understanding timestamps
• Working with links
• Utilizing named pipes (FIFOs)
• Managing sockets
• Handling device files
• Working with special device files
• Navigating procfs and sysfs

Mastering Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Navigating the file manager within MC
• Utilizing command-line shortcuts in MC
• Using the internal editor in MC
• Using the internal viewer in MC
• Leveraging MC auto-start features
• Accessing MC's FTP virtual filesystem

The standard Unix-like work environment

• Understanding the login shell
• Customizing bash
• Utilizing special key strokes
• Using the pager
• Setting a default text editor
• Exiting vim effectively
• Recording shell activities
• Executing basic Unix commands

Essential shell commands

• Command execution and environment variables
• The "$LANG" variable
• The "$PATH" variable
• The "$HOME" variable
• Utilizing command line options
• Understanding shell globbing
• Interpreting command return values
• Common command sequences and shell redirection
• Creating command aliases

Unix-like text processing

• Introduction to Unix text tools
• Understanding regular expressions
• Using replacement expressions
• Performing global substitutions with regular expressions
• Extracting data from text file tables
• Scripting snippets for piping commands

Debian package management

Prerequisites for Debian package management

• Configuring packages
• Essential precautions
• Managing long-term upgrades
• Basics of the Debian archive
• Understanding package dependencies
• The event flow of package management
• Initial responses to package management issues

Basic package management operations

• Comparing apt-get/apt-cache with aptitude
• Performing basic package management operations via the command line
• Interactive use of aptitude
• Key bindings in aptitude
• Exploring package views under aptitude
• Search method options with aptitude
• The aptitude regex formula
• Dependency resolution in aptitude
• Reviewing package activity logs

Examples of aptitude operations

• Listing packages with regex matching on package names
• Browsing with regex matching
• Purging removed packages permanently
• Managing auto/manual installation status
• Performing a system-wide upgrade

Advanced package management operations

• Performing advanced package management operations via the command line
• Verifying installed package files
• Implementing safeguards for package issues
• Searching package metadata

Debian package management internals

• Archive metadata
• Top-level "Release" file and authenticity verification
• Archive-level "Release" files
• Fetching package metadata
• Package state for APT
• Package state for aptitude
• Local copies of fetched packages
• Debian package file naming conventions
• Using the dpkg command
• Using the update-alternative command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

Recovery from a broken system

• Addressing incompatibility with old user configurations
• Resolving overlapping files between different packages
• Fixing broken package scripts
• Rescuing the system with the dpkg command
• Recovering package selection data

Tips for package management

• Selecting appropriate Debian packages
• Handling packages from mixed archive sources
• Adjusting candidate versions
• Managing updates and backports
• Automating package downloads and upgrades
• Limiting download bandwidth for APT
• Performing emergency downgrades
• Identifying package uploaders
• Utilizing the equivs package
• Porting packages to stable systems
• Configuring a proxy server for APT
• Managing small public package archives
• Recording and copying system configurations
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Additional resources for package management

System initialization

• Overview of the bootstrapping process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Runlevel management examples
• Default parameters for init scripts
• Managing the hostname
• Configuring the filesystem
• Initializing network interfaces
• Initializing network services
• Managing system messages
• Interpreting kernel messages
• The udev system
• Initializing kernel modules

Authentication and Security

• Standard Unix authentication
• Managing account and password information
• Creating strong passwords
• Generating encrypted passwords
• Understanding PAM and NSS
• Configuration files accessed by PAM and NSS
• Modern centralized system management
• Understanding why GNU su does not support the wheel group
• Implementing stricter password rules
• Exploring other access controls
• Using sudo
• Utilizing SELinux and AppArmor
• Restricting access to specific server services
• Ensuring authentication security
• Securing passwords over the Internet
• Using Secure Shell
• Implementing extra security measures for the Internet
• Securing the root password

Network setup

Basic network infrastructure

• Understanding domain names
• Configuring hostname resolution
• Managing network interface names
• Defining network address ranges for the LAN
• Supporting network devices

Modern network configuration for desktops

• Utilizing GUI network configuration tools

Low-level network configuration

• Using Iproute2 commands
• Performing safe low-level network operations

Network optimization

• Identifying optimal MTU
• Setting MTU
• Optimizing WAN TCP

Netfilter infrastructure

Network applications

The mail system

• Basics of modern mail services
• Mail configuration strategies for workstations

Mail transport agent (MTA) and Mail user agent (MUA)

• Overview of exim4
• Basic MUA - Mutt

Mail delivery agent (MDA) with filtering

• Configuring maildrop
• Configuring procmail
• Redelivering mbox contents

POP3/IMAP4 server

Remote access server and utility (SSH)

• SSH basics
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Managing compatibility with non-standard SSH clients
• Setting up ssh-agent
• Shutting down remote systems via SSH
• Troubleshooting SSH

Other network application servers

Other network application clients

Diagnosing system daemons

The X Window System

• Setting up the desktop environment
• Understanding the server/client relationship
• Configuring the X server
• Starting the X Window System
• Starting an X session with gdm
• Customizing the X session (traditional method)
• Customizing the X session (modern method)
• Connecting a remote X client via SSH
• Securing X terminals over the Internet
• X applications
• X office applications
• X utility applications

System tips

The screen program

• Use cases for screen(1)
• Key bindings for the screen command

Data recording and presentation

• Understanding the log daemon
• Using log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Colorizing shell echo output
• Colorizing commands
• Recording editor activities for complex repetitions
• Recording the graphic image of an X application
• Recording changes in configuration files

Data storage tips

• Disk partition configuration
• Accessing partitions using UUID
• Filesystem configuration
• Creating filesystems and checking integrity
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock
• Optimizing hard disk performance
• Using SMART to predict hard disk failure
• Expanding usable storage space via LVM
• Expanding usable storage space by mounting another partition
• Expanding usable storage space using symlinks
• Expanding usable storage space using aufs

Data encryption tips

• Encrypting removable disks with dm-crypt/LUKS
• Encrypting swap partitions with dm-crypt
• Automatically encrypting files with eCryptfs
• Automatically mounting eCryptfs

Monitoring, controlling, and starting program activities

• Timing a process
• Understanding scheduling priority
• Using the ps command
• Using the top command
• Listing files opened by a process
• Tracing program activities
• Identifying processes using files or sockets
• Repeating a command at constant intervals
• Repeating a command across files
• Starting a program from the GUI
• Customizing program startup
• Killing a process
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System maintenance tips

• Identifying logged-in users
• Broadcasting warnings to all users
• Identifying hardware
• Configuring hardware
• Managing system and hardware time
• Configuring the terminal
• Setting up the sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• Checking system security and integrity

The kernel

• Configuring kernel parameters
• Managing kernel headers
• Compiling the kernel and related modules
• Compiling the kernel source using Debian standard methods
• Compiling module source using Debian standard methods
• Handling non-free hardware drivers

Virtualized systems

• Virtualization tools
• Virtualization workflow
• Mounting virtual disk image files
• Using chroot systems
• Managing multiple desktop systems

Data management

Sharing, copying, and archiving

• Archive and compression tools
• Copy and synchronization tools
• Archive idioms
• Copy idioms
• File selection idioms
• Backup and recovery strategies
• Backup utility suites
• Example script for system backup
• Script for data backup
• Using removable storage devices
• Sharing data via the network
• Archive media

Handling binary data

• Viewing and editing binary data
• Manipulating files without mounting the disk
• Understanding data redundancy
• Data file recovery and forensic analysis
• Splitting large files into smaller ones
• Clearing file contents
• Creating dummy files
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Undeleting deleted but still open files
• Searching for all hard links
• Understanding invisible disk space consumption

Data security infrastructure

• Key management for GnuPG (signing and encrypting)
• Using MD5 sums