Debian Administration Training Course

Debian Distribution

Introduction to Debian

• Selecting the appropriate Debian version
• Accessing Debian support and resources
• The Debian community

Console Fundamentals

• Understanding the shell prompt
• The shell prompt within the X environment
• Root account and root shell prompt (su, sudo, executing programs as root under X)
• GUI-based system administration tools
• Virtual consoles
• Exiting the command prompt
• Shutting down the system
• Restoring a stable console state
• Recommended additional packages for beginners
• Creating an extra user account
• Configuring sudo

Filesystem Management

• Filesystem permissions
• Controlling permissions for new files via umask
• Group-based user permissions
• Timestamps
• Symbolic and hard links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• procfs and sysfs virtual filesystems

Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Using the MC file manager
• Command-line shortcuts within MC
• The built-in MC editor
• The built-in MC viewer
• MC auto-start capabilities
• MC's FTP virtual filesystem support

Foundational Unix-like Work Environment

• The login shell
• Tailoring bash configuration
• Special key combinations
• Using the pager utility
• Setting a default text editor
• Exiting vim
• Logging shell activities
• Essential Unix commands

Simple Shell Command Execution

• Command execution and environment variables
• The "$LANG" variable
• The "$PATH" variable
• The "$HOME" variable
• Command-line options
• Shell globbing
• Command return values
• Common command sequences and shell redirection
• Command aliases

Unix-like Text Processing

• Essential Unix text tools
• Regular expressions
• Replacement patterns
• Global substitution using regular expressions
• Extracting data from text-based tables
• Script snippets for command piping

Debian Package Management

Prerequisites for Debian Package Management

• Package configuration
• Basic safety precautions
• Managing continuous upgrades
• Debian archive fundamentals
• Package dependencies
• Event flow in package management
• Initial steps for resolving package management issues

Core Package Management Operations

• Comparing apt-get/apt-cache with aptitude
• Basic package management via command line
• Interactive usage of aptitude
• aptitude key bindings
• Package views in aptitude
• Search options in aptitude
• aptitude regex formulas
• Dependency resolution in aptitude
• Package activity logging

aptitude Operation Examples

• Listing packages via regex matching on names
• Browsing with regex matches
• Completely purging removed packages
• Managing auto/manual install status
• System-wide upgrades

Advanced Package Management Operations

• Advanced command-line package management
• Verifying installed package files
• Mitigating package issues
• Searching package metadata

Internal Mechanisms of Debian Package Management

• Archive metadata
• Top-level "Release" file 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
• The dpkg command
• The update-alternatives command
• The dpkg-statoverride command
• The dpkg-divert command

System Recovery from Breakage

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

Package Management Best Practices

• Selecting the right Debian packages
• Using packages from mixed archive sources
• Adjusting candidate versions
• Managing Updates and Backports
• Automating package download and upgrade
• Limits on APT download bandwidth
• Emergency package downgrades
• Identifying package uploaders
• Using the equivs package
• Porting packages to stable systems
• Configuring APT proxy servers
• Setting up 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 bootstrapping process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Runlevel management examples
• Default parameters for init scripts
• Hostname configuration
• Filesystem setup
• 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 data
• Creating strong passwords
• Generating encrypted passwords
• PAM and NSS roles
• Configuration files for PAM and NSS
• Modern centralized system management
• "Why GNU su does not support the wheel group"
• Enforcing strict password rules
• Other access control methods
• Using sudo
• SELinux and AppArmor
• Restricting access to specific server services
• Authentication security
• Secure password transmission over the Internet
• Secure Shell (SSH)
• Additional internet security measures
• Protecting the root password

Network Setup

Basic Network Infrastructure

• Domain names
• Hostname resolution
• Network interface naming
• LAN network address ranges
• Network device support

Modern Desktop Network Configuration

• GUI-based network configuration tools

Low-Level Network Configuration

• Iproute2 commands
• Safe low-level network operations

Network Optimization

• Determining the optimal MTU
• Setting MTU values
• WAN TCP optimization

Netfilter Infrastructure

Network Applications

Mail System

• Modern mail service fundamentals
• Mail configuration strategies for workstations

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

• exim4 overview
• Basic MUA usage with Mutt

Mail Delivery Agent (MDA) with Filtering

• maildrop configuration
• procmail configuration
• Redelivering mbox content

POP3/IMAP4 Server

Remote Access Server and Utilities (SSH)

• SSH fundamentals
• Port forwarding for SMTP/POP3 tunneling
• Passwordless remote connections
• Handling non-standard 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
• Server/client relationships
• The X server
• Starting the X Window System
• Starting X sessions with gdm
• Customizing X sessions (classic method)
• Customizing X sessions (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
• Custom text data display
• Custom time and date display
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repetitions
• Capturing X application graphics
• Tracking configuration file changes

Data Storage Tips

• Disk partition configuration
• Accessing partitions via UUID
• Filesystem configuration
• Filesystem creation and integrity checks
• Filesystem optimization via mount options
• Filesystem optimization via superblocks
• Hard disk optimization
• Predicting hard disk failure using SMART
• Expanding storage space with 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 with eCryptfs
• Automatic eCryptfs mounting

Monitoring, Controlling, and Starting Program Activities

• Timing processes
• Scheduling priority
• The ps command
• The top command
• Listing files opened by a process
• Tracing program activity
• Identifying processes using specific files or sockets
• Repeating commands at fixed intervals
• Looping commands over files
• Launching programs from the GUI
• Customizing startup programs
• Terminating processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• The Alt-SysRq key

System Maintenance Tips

• Identifying active users
• Warning all users
• Hardware identification
• Hardware configuration
• System and hardware time synchronization
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Memory usage monitoring
• System security and integrity checks

The Kernel

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

Virtualized Systems

• Virtualization tools
• Virtualization workflows
• Mounting virtual disk images
• Chroot systems
• Managing multiple desktop systems

Data Management

Sharing, Copying, and Archiving

• Archive and compression tools
• Copy and synchronization tools
• Common archiving idioms
• Common copying idioms
• Common file selection idioms
• Backup and recovery
• Backup utility suites
• Example system backup scripts
• Data backup copy scripts
• Removable storage devices
• Sharing data over the 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
• Clearing file contents
• Creating dummy files
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Recovering deleted but open files
• Finding all hard links
• Invisible disk space consumption

Data Security Infrastructure

• GnuPG key management (signing and encryption)
• MD5 checksums