Debian Administration Training Course

Debian Distribution

What is Debian?

• Selecting the appropriate Debian version
• Debian support resources and community assistance
• Engaging with the Debian community

Console Fundamentals

• Understanding the shell prompt
• Navigating the shell prompt within the X environment
• Managing the root account and root shell prompt (using su, sudo, and running programs as root under X)
• Utilizing GUI system administration tools
• Working with virtual consoles
• Exiting the command prompt properly
• Safely shutting down the system
• Restoring a functional console
• Recommended additional packages for beginners
• Creating an extra user account
• Configuring sudo

Understanding the Filesystem

• Filesystem permission models
• Controlling permissions for new files via umask
• Managing permissions for user groups
• Working with timestamps
• Creating and managing links
• Using named pipes (FIFOs)
• Understanding sockets
• Working with device files
• Special device file types
• Exploring procfs and sysfs

Mastering Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Using the MC file manager
• Advanced command-line techniques in MC
• Navigating the internal MC editor
• Using the internal MC viewer
• Configuring auto-start features
• Accessing the FTP virtual filesystem in MC

Essential Unix-like Work Environment

• Understanding the login shell
• Customizing bash behavior
• Utilizing special keystrokes
• Employing the pager tool
• Setting a default text editor
• Exiting vim effectively
• Logging shell activities
• Executing basic Unix commands

Basic 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
• Implementing typical command sequences and shell redirection
• Creating command aliases

Text Processing in Unix-like Systems

• Overview of Unix text processing tools
• Working with regular expressions
• Using replacement expressions
• Performing global substitutions with regular expressions
• Extracting data from text file tables
• Writing script snippets for command piping

Debian Package Management

Prerequisites for Package Management

• Configuring packages
• Essential precautions
• Managing continuous upgrades
• Basics of the Debian archive
• Understanding package dependencies
• Understanding the package management event flow
• Initial troubleshooting for package management issues

Core Package Management Operations

• Comparing apt-get/apt-cache with aptitude
• Performing basic package management operations via command line
• Interactive usage of aptitude
• aptitude key bindings
• Navigating package views in aptitude
• Search method options in aptitude
• Understanding the aptitude regex formula
• Dependency resolution within aptitude
• Reviewing package activity logs

Examples of aptitude Operations

• Listing packages using regex matching on names
• Browsing using regex matching
• Permanently purging removed packages
• Cleaning up auto vs. manual installation statuses
• Performing a system-wide upgrade

Advanced Package Management Operations

• Executing advanced package management operations via command line
• Verifying installed package files
• Establishing safeguards against package issues
• Searching package metadata

Debian Package Management Internals

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

Recovery from System Breakage

• Handling incompatibilities with old user configurations
• Resolving conflicts between packages with overlapping files
• Fixing broken package scripts
• Rescuing the system using the dpkg command
• Recovering package selection data

Tips for Effective 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 APT download bandwidth
• Performing emergency downgrades
• Identifying the package uploader
• Using the equivs package
• Porting packages to stable systems
• Configuring a proxy server for APT
• Utilizing small public package archives
• Recording and copying system configurations
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Further reading for package management

System Initialization

• Overview of the boot strap process
• BIOS, boot loader, and mini-Debian system
• Understanding runlevels
• Configuring runlevels
• Runlevel management examples
• Default parameters for init scripts
• Setting the hostname
• Filesystem initialization
• Network interface initialization
• Network service initialization
• Understanding system messages
• Interpreting kernel messages
• The udev system
• Kernel module initialization

Authentication and Security

• Standard Unix authentication mechanisms
• Managing account and password information
• Best practices for strong passwords
• Creating 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
• Additional access control measures
• Using sudo
• SELinux and Apparmor
• Restricting access to specific server services
• Authentication security practices
• Secure password transmission over the Internet
• Secure Shell (SSH)
• Additional security measures for the Internet
• Securing the root password

Network Setup

Basic Network Infrastructure

• Managing the domain name
• Hostname resolution
• Network interface naming
• LAN network address ranges
• Network device support

Modern Network Configuration for Desktops

• Using GUI network configuration tools

Low-Level Network Configuration

• Iproute2 commands
• Safe low-level network operations

Network Optimization

• Finding the optimal MTU
• Setting the MTU
• WAN TCP optimization

Netfilter Infrastructure

Network Applications

The Mail System

• Fundamentals 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 fundamentals
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Managing incompatible SSH clients
• Setting up ssh-agent
• Shutting down remote systems via SSH
• SSH troubleshooting

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
• The X server
• Starting the X Window System
• Starting an X session with gdm
• Customizing the X session (classic method)
• Customizing the X session (new 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

• The log daemon
• Log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repeats
• 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
• Filesystem creation and integrity checks
• Filesystem optimization via mount options
• Filesystem optimization via superblock
• Hard disk optimization
• 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
• Creating encrypted 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 while looping over files
• Starting a program from the GUI
• Customizing startup programs
• Killing a process
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Checking who is on the system
• Notifying all users
• Hardware identification
• Hardware configuration
• System and hardware time management
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• System security and integrity checks

The Kernel

• Kernel parameters
• Kernel headers
• Compiling the kernel and related modules
• Compiling the kernel source: Debian standard method
• Compiling module source: Debian standard method
• Non-free hardware drivers

Virtualized Systems

• Virtualization tools
• Virtualization workflow
• Mounting virtual disk image files
• The Chroot system
• Running multiple desktop systems

Data Management

Sharing, Copying, and Archiving

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

Binary Data

• Viewing and editing binary data
• Manipulating files without mounting the disk
• 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 hardlinks
• Accounting for invisible disk space consumption

Data Security Infrastructure

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