Debian Administration Training Course

The Debian Distribution

Understanding Debian

• Selecting a Debian release
• Accessing Debian support and assistance
• The Debian community ecosystem

Console Fundamentals

• Working with the shell prompt
• The shell prompt in X environments
• Managing root access: root shell prompt (su, sudo, executing programs as root in X)
• GUI-based system administration utilities
• Switching between virtual consoles
• Exiting the command prompt
• Shutting down the system properly
• Restoring a responsive console state
• Recommended additional packages for beginners
• Creating secondary user accounts
• Configuring sudo permissions

The Filesystem

• Managing filesystem permissions
• Controlling default permissions for new files via umask
• Group-based permission management
• File timestamps
• Hard and symbolic links
• Named pipes (FIFOs)
• Network sockets
• Standard device files
• Special device files
• procfs and sysfs interfaces

Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Using the file manager within MC
• Command-line shortcuts in MC
• Editing text with MC’s internal editor
• Viewing files with MC’s internal viewer
• Automating tasks with MC’s auto-start features
• Accessing FTP via MC’s virtual filesystem

The Basic Unix-like Work Environment

• The login shell
• Tailoring bash behavior
• Using special keyboard shortcuts
• Navigating with the pager
• Setting a default text editor
• Exiting vim effectively
• Logging shell session activities
• Essential Unix commands

The Simple Shell Command

• Executing commands and using environment variables
• The "$LANG" variable
• The "$PATH" variable
• The "$HOME" variable
• Using command-line options
• Shell globbing patterns
• Interpreting command return values
• Common command sequences and shell redirection
• Creating command aliases

Unix-like Text Processing

• Essential Unix text utilities
• Using regular expressions
• Working with replacement expressions
• Performing global substitutions with regex
• Extracting data from tabular text files
• Writing script snippets for command piping

Debian Package Management

Prerequisites for Debian Package Management

• Configuring packages
• Basic safety precautions
• Living with continuous upgrades
• Basics of Debian archives
• Understanding package dependencies
• The workflow of package management events
• Initial steps to resolve package management issues

Basic Package Management Operations

• Comparing apt-get/apt-cache vs. aptitude
• Performing basic operations via the command line
• Interactive usage of aptitude
• Key shortcuts for aptitude
• Browsing package views in aptitude
• Search options in aptitude
• Using regex formulas in aptitude
• Resolving dependencies with aptitude
• Reviewing package activity logs

Examples of aptitude Operations

• Listing packages using regex name matching
• Browsing with regex-based filtering
• Permanently purging removed packages
• Organizing auto vs. manual installation statuses
• Executing a system-wide upgrade

Advanced Package Management Operations

• Advanced command-line package operations
• Verifying installed package files
• Protecting the system from package-related issues
• Searching package metadata

Debian Package Management Internals

• Understanding archive metadata
• Top-level "Release" files and authenticity verification
• Archive-level "Release" files
• Fetching package metadata
• Package state management in APT
• Package state management in aptitude
• Local caching of downloaded 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

Recovering from a Broken System

• Handling incompatibilities with old user configurations
• Resolving file conflicts between packages
• Fixing broken package scripts
• Rescuing the system using dpkg
• Restoring package selection data

Tips for Package Management

• How to select Debian packages
• Managing 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 package uploaders
• Using the equivs package
• Porting packages to stable systems
• Configuring a proxy server for APT
• Setting up small public package archives
• Recording and duplicating system configurations
• Converting or installing alien binary packages
• Extracting packages without using dpkg
• Further reading on package management

System Initialization

• Overview of the boot strap process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Setting the hostname
• Filesystem initialization
• Network interface setup
• Network service startup
• Processing system messages
• Reading kernel messages
• The udev system
• Initializing kernel modules

Authentication and Security

• Standard Unix authentication methods
• Managing account and password details
• Creating strong passwords
• Generating encrypted passwords
• Working with PAM and NSS
• Configuring files used by PAM and NSS
• Implementing modern centralized system management
• "Why GNU su does not support the wheel group"
• Enforcing stricter password policies
• Implementing other access controls
• Using sudo effectively
• Applying SELinux and Apparmor
• Restricting access to specific server services
• Enhancing authentication security
• Transmitting passwords securely over the Internet
• Using Secure Shell (SSH)
• Additional security measures for Internet connections
• Securing the root password

Network Setup

Basic Network Infrastructure

• Domain names
• Hostname resolution
• Naming network interfaces
• Defining LAN network address ranges
• Network device support

Modern Network Configuration for Desktops

• Using GUI network configuration tools

Low-Level Network Configuration

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

Network Optimization

• Determining optimal MTU
• Configuring MTU settings
• Optimizing TCP for WAN connections

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)

• Introduction to exim4
• Using Mutt as a basic MUA

Mail Delivery Agent (MDA) with Filters

• Configuring maildrop
• Configuring procmail
• Redelivering mbox contents

POP3/IMAP4 Server

Remote Access Server and Utilities (SSH)

• SSH fundamentals
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Handling non-standard SSH clients
• Setting up ssh-agent
• Shutting down remote systems via SSH
• Diagnosing SSH issues

Other Network Application Servers

Other Network Application Clients

Diagnosing System Daemons

The X Window System

• Setting up the desktop environment
• Understanding server/client relationships
• The X server
• Launching the X Window System
• Starting X sessions with gdm
• Customizing X sessions (traditional method)
• Customizing X sessions (modern method)
• Connecting remote X clients via SSH
• Using secure X terminals over the Internet
• X-based applications
• X office suite applications
• X utility applications

System Tips

The Screen Program

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

Data Recording and Presentation

• Using the log daemon
• Analyzing logs
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Using colorized shell echo
• Colorizing command outputs
• Recording editor actions for complex repetitions
• Capturing graphics from X applications
• Tracking changes in configuration files

Data Storage Tips

• Configuring disk partitions
• Accessing partitions using UUID
• Filesystem configuration
• Creating and checking filesystem integrity
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock settings
• Hard disk optimization
• Predicting hard disk failures using SMART
• Expanding storage space using LVM
• Expanding storage by mounting additional partitions
• Expanding storage using symbolic links
• Expanding storage using aufs

Data Encryption Tips

• Encrypting removable disks with dm-crypt/LUKS
• Encrypting swap partitions with dm-crypt
• Automatic file encryption using eCryptfs
• Automatic mounting of eCryptfs volumes

Monitoring, Controlling, and Starting Program Activities

• Timing processes
• Managing 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 commands at constant intervals
• Looping commands over files
• Launching programs from the GUI
• Customizing startup programs
• Terminating processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Identifying users on the system
• Issuing system-wide warnings
• Identifying hardware
• Configuring hardware
• Managing system and hardware time
• Terminal configuration
• Sound infrastructure setup
• Disabling screen savers
• Disabling beep sounds
• Monitoring memory usage
• Checking system security and integrity

The Kernel

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

Virtualized Systems

• Virtualization tools
• Virtualization workflows
• 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
• Common idioms for archiving
• Common idioms for copying
• Common idioms for file selection
• Backup and recovery procedures
• Backup utility suites
• Example script for system backup
• Script for data backup copying
• Managing removable storage devices
• Sharing data over the network
• Using archive media

Binary Data

• Viewing and editing binary data
• Manipulating files without mounting disks
• Data redundancy
• Data file recovery and forensic analysis
• Splitting large files into smaller chunks
• Clearing file contents
• Creating dummy files
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Recovering deleted but still open files
• Finding all hardlinks
• Identifying hidden disk space consumption

Data Security Infrastructure

• GnuPG key management (signing and encryption)
• Calculating MD5 sums