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
• Using the shell prompt within X environments
• Managing the root account and shell prompt (using su, sudo, and running root-level programs under X)
• Utilizing GUI-based system administration tools
• Navigating virtual consoles
• Exiting the command prompt
• Properly shutting down the system
• Restoring a functional console state
• Recommended packages for beginners
• Setting up an additional user account
• Configuring sudo access

The Filesystem

• Understanding filesystem permissions
• Controlling permissions for new files via umask
• Managing group-based permissions
• Working with file timestamps
• Creating and managing links
• Using named pipes (FIFOs)
• Understanding sockets
• Handling device files
• Working with special device files
• Exploring procfs and sysfs

Midnight Commander (MC)

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

The Standard Unix-like Work Environment

• Understanding the login shell
• Customizing the bash shell
• Mastering special keyboard shortcuts
• Using the pager
• Setting a default text editor
• Navigating out of vim
• Logging shell activity
• 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 redirections
• Creating command aliases

Unix-like Text Processing

• Essential Unix text utilities
• Working with regular expressions
• Using replacement expressions
• Performing global substitutions with regular expressions
• Extracting data from text-based tables
• Writing script snippets for command piping

Debian Package Management

Prerequisites for Debian Package Management

• Configuring packages
• Essential precautions
• Managing continuous upgrades
• Understanding the Debian archive structure
• Understanding package dependencies
• Tracking the package management workflow
• Initial responses to package management issues

Core Package Management Operations

• Comparing apt-get/apt-cache vs. aptitude
• Performing basic package management via the command line
• Interactive usage of aptitude
• Mastering aptitude key bindings
• Navigating package views in aptitude
• Search options and methods in aptitude
• Using the aptitude regex formula
• Resolving dependencies with aptitude
• Reviewing package activity logs

Examples of aptitude Operations

• Listing packages using regex matching on package names
• Browsing packages via regex matching
• Completely purging removed packages
• Adjusting auto/manual installation status
• Performing a system-wide upgrade

Advanced Package Management Operations

• Executing advanced package management commands
• Verifying installed package files
• Preventing package-related issues
• Searching package metadata

Internals of Debian Package Management

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

Recovering from a Broken System

• Handling incompatibilities with legacy user configurations
• Resolving conflicts from overlapping files in different packages
• Repairing broken package scripts
• Rescuing systems using the dpkg command
• Restoring package selection data

Tips for Package Management

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

System Initialization

• Overview of the bootstrapping process
• Understanding BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Configuring the hostname
• Filesystem setup during boot
• Initializing network interfaces
• Initializing network services
• Managing system messages
• Managing kernel messages
• Understanding the udev system
• Initializing kernel modules

Authentication and Security

• Standard Unix authentication mechanisms
• Managing account and password information
• Creating strong passwords
• Generating encrypted passwords
• Understanding PAM and NSS
• Configuration files used by PAM and NSS
• Modern centralized system management
• Understanding GNU su and the wheel group
• Enforcing stricter password policies
• Implementing additional access controls
• Utilizing sudo
• Working with SELinux and AppArmor
• Restricting access to specific server services
• Ensuring authentication security
• Securing password transmission over the Internet
• Using Secure Shell (SSH)
• Implementing extra security measures for Internet exposure
• Securing the root password

Network Setup

Basic Network Infrastructure

• Understanding domain names
• Configuring hostname resolution
• Identifying network interface names
• Defining LAN network address ranges
• Supported network devices

Modern Desktop Network Configuration

• Using GUI network configuration tools

Low-Level Network Configuration

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

Network Optimization

• Identifying the optimal MTU
• Configuring MTU settings
• Optimizing WAN TCP performance

Netfilter Infrastructure

Network Applications

Mail Systems

• 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 Servers

Remote Access Server and Utility (SSH)

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

Other Network Application Servers

Other Network Application Clients

Daemon System Diagnosis

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 (classic method)
• Customizing the X session (modern method)
• Connecting remote X clients via SSH
• Using secure X terminals over the Internet
• X applications overview
• 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

• Utilizing the log daemon
• Using log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Colorizing shell echo output
• Colorizing command outputs
• Recording editor activities for complex repetitions
• Recording graphical images of X applications
• Tracking changes in configuration files

Data Storage Tips

• Configuring disk partitions
• Accessing partitions using UUIDs
• Configuring filesystems
• Creating and checking filesystem integrity
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock adjustments
• Optimizing hard disk performance
• Using SMART to predict hard disk failures
• Expanding usable storage via LVM
• Expanding usable storage by mounting additional partitions
• Expanding usable storage using symlinks
• Expanding usable storage using aufs

Data Encryption Tips

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

Monitoring, Controlling, and Starting Program Activities

• Timing process execution
• Adjusting scheduling priorities
• 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
• Repeating commands while looping over files
• Starting programs from the GUI
• Customizing startup programs
• Killing processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System Maintenance Tips

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

The Kernel

• Understanding 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 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 and best practices
• Copy idioms and best practices
• File selection idioms
• Backup and recovery strategies
• Backup utility suites
• Example script for system backup
• Script for data backup copying
• Managing removable storage devices
• Sharing data via network
• Archive media selection

Binary Data

• Viewing and editing binary data
• Manipulating files without mounting disks
• Data redundancy strategies
• Data file recovery and forensic analysis
• Splitting large files into smaller chunks
• Clearing file contents securely
• Creating dummy files
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Undeleting files that are deleted but still open
• Searching for all hardlinks
• Accounting for invisible disk space consumption

Data Security Infrastructure

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