Debian Administration Training Course

Debian Distribution

Understanding Debian

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

Console Fundamentals

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

Filesystem Management

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

Midnight Commander (MC)

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

The Standard Unix-like Work Environment

• Understanding the login shell
• Customizing bash
• Using special keystrokes
• Utilizing the pager
• 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
• Using shell globbing
• Interpreting command return values
• Employing typical command sequences and shell redirection
• Creating command aliases

Unix-like Text Processing

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

Debian Package Management

Prerequisites for Debian Package Management

• Package configuration
• Essential precautions
• Managing continuous upgrades
• Basics of the Debian archive
• Understanding package dependencies
• The workflow of package management events
• Initial troubleshooting steps for package issues

Basic Package Management Operations

• Comparing apt-get/apt-cache versus aptitude
• Performing basic package management via the command line
• Interactive use of aptitude
• Key bindings in aptitude
• Navigating package views in aptitude
• Search method options within aptitude
• Understanding the aptitude regex formula
• Resolving dependencies with aptitude
• Reviewing package activity logs

Examples of aptitude Operations

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

Advanced Package Management Operations

• Executing advanced package management via the command line
• Verifying installed package files
• Precautionary measures against package issues
• Searching package metadata

Internals of Debian Package Management

• Archive metadata structure
• Understanding the top-level "Release" file and authenticity
• Archive-level "Release" files
• Fetching package metadata
• APT package states
• aptitude package states
• Local caches of fetched packages
• Debian package naming conventions
• Using the dpkg command
• Using the update-alternatives command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

Recovery from System Breakage

• Handling incompatibilities with old user configurations
• Managing different packages with overlapping files
• Fixing broken package scripts
• Rescue operations using the dpkg command
• Recovering package selection data

Tips for Package Management

• Selecting Debian packages effectively
• Handling packages from mixed archive sources
• Adjusting candidate versions
• Understanding updates and backports
• Automating package downloads and upgrades
• Limiting APT download bandwidth
• Emergency downgrading procedures
• Identifying package uploaders
• Using the equivs package
• Porting packages to stable systems
• Configuring proxy servers for APT
• Utilizing 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 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 initialization
• Network service initialization
• System messages
• Kernel messages
• The udev system
• Kernel module initialization

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 GNU su and the wheel group
• Implementing stricter password rules
• Other access control mechanisms
• Using sudo
• SELinux and AppArmor
• Restricting access to specific server services
• Ensuring authentication security
• Secure password handling over the Internet
• Secure Shell (SSH)
• Additional security measures for Internet exposure
• Securing the root password

Network Configuration

Basic Network Infrastructure

• Understanding domain names
• Hostname resolution
• Network interface naming conventions
• Defining LAN network address ranges
• Network device support

Modern Desktop Network Configuration

• Using GUI network configuration tools

Low-Level Network Configuration

• Using Iproute2 commands
• Safely performing low-level network operations

Network Optimization

• Determining the optimal MTU
• Setting MTU values
• Optimizing WAN TCP performance

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 Filters

• 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
• 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 (modern method)
• Connecting remote X clients 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
• Colorizing shell echo output
• Colorizing command output
• Recording editor activities for complex repetition
• Recording X application graphics
• Recording changes in configuration files

Data Storage Tips

• Disk partition configuration
• Accessing partitions using UUID
• Filesystem configuration
• Creating and checking filesystem 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 additional partitions
• 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
• Setting 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
• Looping a command 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 logged into the system
• Notifying all users
• Identifying hardware
• Configuring hardware
• Setting system and hardware time
• Configuring the terminal
• Setting up the sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• Performing system security and integrity checks

The Kernel

• Kernel parameters
• Kernel headers
• Compiling the kernel and related modules
• Compiling 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
• Using chroot systems
• 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
• Backup utility suites
• Example script for system backup
• Script for data backup copying
• Using removable storage devices
• Sharing data via the network
• 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 files
• 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
• Identifying invisible disk space consumption

Data Security Infrastructure

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