Debian Administration Training Course

Debian Distribution

Introduction to Debian

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

Console Fundamentals

• Understanding the shell prompt
• Utilizing the shell prompt within the X environment
• Managing the root account and root shell prompt (using su, sudo, and executing programs as root under X)
• Leveraging GUI system administration tools
• Interacting with virtual consoles
• Exiting the command prompt
• Shutting down the system
• Restoring a functional console state
• Recommended additional packages for beginners
• Creating supplementary user accounts
• Configuring sudo

The Filesystem

• Filesystem permissions
• Controlling permissions for newly created files via umask
• Managing permissions for user groups
• Understanding timestamps
• Working with links
• Using named pipes (FIFOs)
• Handling sockets
• Managing device files
• Special device files
• procfs and sysfs

Midnight Commander (MC)

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

The Basic Unix-like Work Environment

• The login shell
• Customizing bash
• Special keystrokes
• Using the pager
• Setting a default text editor
• Exiting vim
• Logging shell activities
• Essential Unix commands

The Simple Shell Command

• 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

• Unix text tools
• Regular expressions
• Replacement expressions
• Global substitution using regular expressions
• Extracting data from text file tables
• Script snippets for piping commands

Debian Package Management

Prerequisites for Debian Package Management

• Package configuration
• Basic safety precautions
• Managing systems with continuous upgrades
• Debian archive fundamentals
• Package dependencies
• The workflow of package management events
• Initial responses to package management issues

Basic Package Management Operations

• Comparing apt-get/apt-cache and aptitude
• Core package management operations via the command line
• Interactive usage of aptitude
• aptitude key bindings
• Package views in aptitude
• Search options in aptitude
• The aptitude regular expression formula
• Dependency resolution in aptitude
• Package activity logs

Examples of aptitude Operations

• Listing packages using regular expression matching on names
• Browsing via regular expression matching
• Thoroughly purging removed packages
• Organizing auto/manual install status
• Performing system-wide upgrades

Advanced Package Management Operations

• Advanced package management commands
• Verifying installed package files
• Mitigating package issues
• Searching package metadata

Debian Package Management Internals

• Archive metadata
• Top-level "Release" file and authenticity
• Archive-level "Release" files
• Fetching package metadata
• Package state in APT
• Package state in aptitude
• Local storage of fetched packages
• Debian package naming conventions
• The dpkg command
• The update-alternative command
• The dpkg-statoverride command
• The dpkg-divert command

Recovering from a Broken System

• Handling incompatibility with legacy user configurations
• Managing packages with overlapping files
• Repairing broken package scripts
• Rescue operations using the dpkg command
• Restoring package selection data

Tips for Package Management

• Selecting appropriate Debian packages
• Sourcing packages from mixed archives
• Adjusting candidate versions
• Managing Updates and Backports
• Automating package download and upgrade
• Limiting APT download bandwidth
• Emergency downgrading procedures
• Identifying package uploaders
• Using the equivs package
• Porting packages to stable systems
• Configuring a proxy server for APT
• Setting up a small public package archive
• Recording and copying system configurations
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Further resources on package management

System Initialization

• Overview of the bootstrapping process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for each init script
• 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 details
• Creating strong passwords
• Generating encrypted passwords
• PAM and NSS
• Configuration files used by PAM and NSS
• Modern centralized system management
• "Why GNU su does not support the wheel group"
• Implementing stricter password rules
• Additional access controls
• Using sudo
• SELinux and AppArmor
• Restricting access to specific server services
• Securing authentication processes
• Transmitting secure passwords over the internet
• Secure Shell (SSH)
• Additional internet security measures
• Securing 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 network configuration tools

Low-Level Network Configuration

• Iproute2 commands
• Safe low-level network operations

Network Optimization

• Identifying the optimal MTU
• Configuring MTU
• WAN TCP optimization

Netfilter Infrastructure

Network Applications

The Mail System

• Foundations of modern mail services
• Mail configuration strategies 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 Server

Remote Access Server and Utilities (SSH)

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

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
• Launching 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 logging shell activities
• Customizing text data display
• Customizing time and date display
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repetitions
• Capturing graphics from X applications
• Tracking changes in configuration files

Data Storage Tips

• Disk partition configuration
• Accessing partitions using UUIDs
• Filesystem configuration
• Creating filesystems and integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblocks
• Hard disk optimization
• Predicting hard disk failures using SMART
• Expanding storage space via LVM
• Expanding storage by mounting additional partitions
• Expanding storage using symlinks
• 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 mounting of eCryptfs

Monitoring, Controlling, and Starting Program Activities

• Timing processes
• Scheduling priorities
• The ps command
• 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
• Starting programs from the GUI
• Customizing program launches
• Terminating processes
• One-time task scheduling
• Regular task scheduling
• The Alt-SysRq key

System Maintenance Tips

• Identifying active system users
• Broadcasting warnings
• Hardware identification
• Hardware configuration
• System and hardware time synchronization
• Terminal configuration
• Sound infrastructure
• Disabling screensavers
• Disabling beep sounds
• Memory usage analysis
• 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 workflows
• Mounting virtual disk image files
• Chroot systems
• Multiple desktop systems

Data Management

Sharing, Copying, and Archiving

• Archive and compression tools
• Copy and synchronization tools
• Archive idioms
• Copy idioms
• File selection idioms
• Backup and recovery
• Backup utility suites
• Example scripts for system backups
• Scripts for data backups
• Removable storage devices
• Sharing data over networks
• 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
• Clearing file contents
• Using dummy files
• Erasing entire hard disks
• Erasing unused areas of hard disks
• Recovering deleted but open files
• Searching for all hard links
• Identifying invisible disk space consumption

Data Security Infrastructure

• Key management for GnuPG (signing and encrypting)
• MD5 checksums