Debian Administration Training Course

Debian Distribution

Understanding Debian

• Selecting a Debian version
• Debian support resources and assistance
• The Debian community

Console Fundamentals

• Understanding the shell prompt
• The shell prompt within the X environment
• Root account management and root shell access (su, sudo, executing programs as root under X)
• GUI-based system administration tools
• Virtual consoles
• Exiting the command prompt
• System shutdown procedures
• Restoring a functional console
• Recommended additional packages for beginners
• Creating additional user accounts
• Configuring sudo

Filesystem Structure

• Filesystem permissions
• Managing permissions for new files using umask
• Group-based permissions
• File timestamps
• Symbolic and hard links
• Named pipes (FIFOs)
• Network and Unix 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 text editor in MC
• The built-in file viewer in MC
• MC auto-start capabilities
• MC's FTP virtual filesystem

Basic Unix-like Work Environment

• The login shell
• Personalizing bash
• Special keyboard shortcuts
• Using a text pager
• Selecting a default text editor
• Exiting vim
• Recording shell session activities
• Essential Unix commands

Basic Shell Commands

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

Unix-like Text Processing

• Unix text utility tools
• Regular expressions
• String replacement expressions
• Global substitutions using regular expressions
• Extracting data from text-based tables
• Script examples for piping commands

Debian Package Management

Prerequisites for Debian Package Management

• Package configuration concepts
• Basic safety measures
• Handling continuous system upgrades
• Foundations of Debian archives
• Understanding package dependencies
• The workflow of package management events
• Initial steps when package management issues arise

Core Package Management Operations

• Comparison of apt-get/apt-cache and aptitude
• Basic command-line package management tasks
• Interactive usage of aptitude
• aptitude keyboard shortcuts
• Package views in aptitude
• Search options in aptitude
• Regular expression formulas in aptitude
• Dependency resolution in aptitude
• Reviewing package activity logs

aptitude Operation Examples

• Listing packages using regex matching on names
• Browsing packages with regex matching
• Permanently purging removed packages
• Organizing auto/manual install status
• Performing system-wide upgrades

Advanced Package Management Operations

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

Internals of Debian Package Management

• Archive metadata structure
• Top-level "Release" file and integrity verification
• Archive-level "Release" files
• Fetching package metadata
• Package states in APT
• Package states in aptitude
• Local caches of downloaded packages
• Naming conventions for Debian package files
• Using the dpkg command
• The update-alternatives command
• The dpkg-statoverride command
• The dpkg-divert command

Recovering a Broken System

• Resolving incompatibilities with old user configurations
• Handling package file overlaps
• Repairing broken package scripts
• Rescue operations using dpkg
• Restoring package selection data

Package Management Tips

• Methods for selecting Debian packages
• Using packages from mixed archive sources
• Adjusting candidate package versions
• Working with Updates and Backports
• Automating package downloads and upgrades
• Limiting APT download bandwidth
• Emergency package downgrades
• 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
• Documenting and replicating system configurations
• Converting or installing non-Debian binary packages
• Extracting package contents without dpkg
• Further reading on package management

System Initialization

• Overview of the boot process
• BIOS, boot loaders, and the mini-Debian system
• The concept of runlevels
• Configuring runlevels
• Example of runlevel management
• Default parameters for init scripts
• Hostname configuration
• Filesystem mounting during boot
• Network interface initialization
• Network service initialization
• System message handling
• Kernel message logging
• The udev system
• Kernel module initialization

Authentication and Security

• Standard Unix authentication methods
• Managing account and password data
• Creating strong passwords
• Generating encrypted passwords
• Understanding PAM and NSS
• Configuration files used by PAM and NSS
• Modern centralized system administration
• Why GNU su does not support the wheel group
• Implementing stricter password policies
• Additional access control mechanisms
• Using sudo
• SELinux and AppArmor
• Restricting access to specific server services
• Securing authentication processes
• Securing passwords over the Internet
• Secure Shell (SSH)
• Additional security measures for internet connectivity
• 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 command usage
• Safe low-level network operations

Network Optimization

• Determining optimal MTU
• Configuring MTU settings
• Optimizing TCP over WAN

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 Utilities (SSH)

• Fundamentals of SSH
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Working with 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 architecture
• 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
• Secure X terminals over the Internet
• X applications
• X office applications
• X utility applications

System Tips

The screen Program

• Use cases for screen(1)
• Keyboard shortcuts for the screen command

Data Recording and Presentation

• The log daemon
• Log analysis tools
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Colorized shell output
• Colorized commands
• Recording editor actions for complex repetitions
• Capturing screenshots of X applications
• Tracking changes in configuration files

Data Storage Tips

• Disk partition configuration
• Accessing partitions via UUID
• Filesystem configuration
• Creating filesystems and checking integrity
• Optimizing filesystems using mount options
• Optimizing filesystems via superblocks
• Hard disk optimization
• Predicting hard disk failures using SMART
• Expanding storage space with LVM
• Expanding storage space by mounting additional partitions
• Expanding storage space using symbolic links
• Expanding 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 process execution
• Scheduling priorities
• Using the ps command
• Using the top command
• Listing files opened by a process
• Tracing program activities
• Identifying processes using specific files or sockets
• Repeating commands at fixed intervals
• Looping commands over files
• Starting programs from the GUI
• Customizing program startup
• Terminating processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Identifying active users on the system
• Issuing warnings to 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 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 images
• The chroot system
• Managing multiple desktop systems

Data Management

Sharing, Copying, and Archiving

• Archive and compression utilities
• Copy and synchronization tools
• Archive idioms
• Copy idioms
• Idioms for file selection
• Backup and recovery strategies
• Backup utility suites
• Example system backup script
• Data backup copy script
• Removable storage devices
• Sharing data over the network
• Archival media

Binary Data

• Viewing and editing binary data
• Manipulating files without mounting disks
• Data redundancy
• Data recovery and forensic analysis
• Splitting large files into smaller ones
• Clearing file contents
• Creating dummy files
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Restoring deleted but still open files
• Finding all hard links
• Hidden disk space consumption

Data Security Infrastructure

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