Debian Administration Training Course

Debian Distribution

Understanding Debian

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

Console Fundamentals

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

Filesystem Management

• Understanding filesystem permissions
• Controlling default permissions for new files: using umask
• Managing permissions for user groups
• Working with timestamps
• Creating and managing links
• Using named pipes (FIFOs)
• Understanding sockets
• Interacting with device files
• Handling special device files
• Navigating procfs and sysfs

Mastering Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Navigating the file manager within MC
• Applying command-line techniques in MC
• Utilizing the built-in text editor in MC
• Using the built-in file viewer in MC
• Leveraging auto-start features of MC
• Navigating FTP virtual filesystems via MC

The Basic Unix-Like Work Environment

• Understanding the login shell
• Customizing the bash environment
• Utilizing special key combinations
• Using text pagers
• Setting a default text editor
• Exiting vim efficiently
• Recording shell session activities
• Familiarity with basic Unix commands

Essential Shell Commands

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

Unix-Like Text Processing

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

Debian Package Management

Prerequisites for Debian Package Management

• Configuring packages
• Essential precautions to take
• Managing the lifecycle of permanent upgrades
• Fundamentals of the Debian archive
• Understanding package dependencies
• Tracing the event flow of package management operations
• Initial troubleshooting steps for package issues

Basic Package Management Operations

• Comparing apt-get/apt-cache with aptitude
• Executing basic package management via command line
• Interactively using aptitude
• Mastering aptitude key bindings
• Navigating package views in aptitude
• Search options available in aptitude
• Understanding the aptitude regex syntax
• Resolving dependencies with aptitude
• Reviewing package activity logs

Aptitude Operations Examples

• Listing packages using regex matching on names
• Browsing packages via regex matching
• Purging removed packages permanently
• Managing auto vs. manual installation status
• Performing a system-wide upgrade

Advanced Package Management Operations

• Executing advanced package management via command line
• Verifying installed package file integrity
• Safeguarding against package-related issues
• Searching within package metadata

Internals of Debian Package Management

• Understanding archive metadata
• Analyzing the top-level "Release" file and its authenticity
• Examining archive-level "Release" files
• Fetching package metadata
• Understanding APT package states
• Understanding aptitude package states
• Managing local copies of fetched packages
• Decoding Debian package file naming conventions
• Utilizing the dpkg command
• Using the update-alternatives command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

Recovering from a Broken System

• Addressing incompatibilities with legacy user configurations
• Handling packages with overlapping files
• Repairing broken package scripts
• Performing rescue operations using the dpkg command
• Recovering package selection data

Tips for Effective Package Management

• Selecting appropriate Debian packages
• Managing packages from mixed archive sources
• Adjusting candidate package versions
• Navigating updates and backports
• Automating package download and upgrade processes
• Limiting bandwidth usage for APT
• Performing emergency downgrades
• Identifying the uploader of a specific package
• Utilizing the equivs package utility
• Porting packages to stable systems
• Configuring proxy servers for APT
• Creating small public package archives
• Recording and backing up system configurations
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Finding further resources on package management

System Initialization

• Overview of the boot strap process
• Understanding BIOS, boot loaders, and mini-Debian systems
• Defining and understanding runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Managing the hostname
• Filesystem initialization steps
• Initializing network interfaces
• Initializing network services
• Viewing system messages
• Monitoring kernel messages
• Understanding the udev system
• Initializing kernel modules

Authentication and Security

• Standard Unix authentication mechanisms
• Managing account and password information
• Crafting strong passwords
• Generating encrypted passwords
• Understanding PAM and NSS
• Identifying configuration files accessed by PAM and NSS
• Implementing modern centralized system management
• Addressing the lack of wheel group support in GNU su
• Enforcing stricter password policies
• Exploring other access control methods
• Configuring sudo privileges
• Implementing SELinux and Apparmor
• Restricting access to specific server services
• Ensuring authentication security
• Safeguarding passwords transmitted over the Internet
• Utilizing Secure Shell (SSH)
• Applying additional security measures for internet-facing services
• Securing the root password

Network Configuration

Foundational Network Infrastructure

• Understanding domain names
• Configuring hostname resolution
• Identifying network interface names
• Determining the LAN network address range
• Ensuring network device compatibility

Modern Desktop Network Configuration

• Utilizing GUI-based network configuration tools

Low-Level Network Configuration

• Using iproute2 commands
• Performing safe low-level network operations

Network Optimization

• Identifying the optimal Maximum Transmission Unit (MTU)
• Configuring MTU settings
• Optimizing TCP performance over WAN connections

Netfilter Infrastructure

Network Applications

The Mail System

• Fundamentals of modern mail services
• Strategizing mail configuration for workstations

Mail Transport Agent (MTA) and Mail User Agent (MUA)

• Overview of exim4
• Basic MUA usage with Mutt

Mail Delivery Agent (MDA) with Filtering

• Configuring maildrop
• Configuring procmail
• Redelivering mbox contents

POP3/IMAP4 Servers

Remote Access Server and Utilities (SSH)

• Foundations of SSH
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords using keys
• Interacting with incompatible SSH clients
• Setting up ssh-agent
• Shutting down remote systems via SSH
• Troubleshooting common SSH issues

Other Network Application Servers

Other Network Application Clients

Diagnostics for System Daemons

The X Window System

• Setting up the desktop environment
• Understanding the server/client relationship
• Configuring the X server
• Launching 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
• Utilizing X applications
• X office productivity tools
• X utility applications

System Tips and Tricks

The Screen Program

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

Data Recording and Presentation

• Configuring the log daemon
• Using log analyzers
• Cleanly recording shell activities
• Customizing text data display formats
• Customizing time and date displays
• Using colorized shell echo commands
• Applying colorization to commands
• Recording editor activities for complex repetition tasks
• Recording the graphical interface of X applications
• Tracking changes in configuration files

Data Storage Tips

• Configuring disk partitions
• Accessing partitions using UUIDs
• Configuring filesystems
• Creating filesystems and performing integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock adjustments
• Optimizing hard disk performance
• Using SMART technology to predict hard disk failures
• Expanding usable storage space via LVM
• Expanding usable storage space by mounting additional partitions
• Expanding usable storage space using symbolic links
• 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 volumes

Monitoring, Controlling, and Starting Program Activities

• Timing process execution
• Setting scheduling priorities
• Using the ps command
• Using the top command
• Listing files opened by a specific 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 auto-started programs
• Killing unresponsive processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key combination

System Maintenance Tips

• Checking who is currently logged in
• Broadcasting warnings to all users
• Identifying hardware components
• Configuring hardware settings
• Managing system and hardware clocks
• Configuring terminal settings
• Understanding the sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• Performing system security and integrity checks

The Linux Kernel

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

Virtualized Systems

• Using virtualization tools
• Navigating virtualization workflows
• Mounting virtual disk image files
• Utilizing chroot environments
• Running multiple desktop systems simultaneously

Data Management

Sharing, Copying, and Archiving

• Utilizing archive and compression tools
• Using copy and synchronization utilities
• Archiving idioms and best practices
• Copying idioms and best practices
• Strategies for selecting files
• Backup and recovery strategies
• Evaluating backup utility suites
• Scripting an example system backup
• Creating a script for data backups
• Managing removable storage devices
• Sharing data over the network
• Selecting archive media

Binary Data Management

• Viewing and editing binary data
• Manipulating files without mounting disks
• Understanding data redundancy
• Data file recovery and forensic analysis
• Splitting large files into smaller segments
• Clearying file contents securely
• 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
• Identifying invisible disk space consumption

Data Security Infrastructure

• Managing keys for GnuPG (signing and encrypting)
• Using MD5 sums for integrity verification