Debian Administration Training Course

Debian Distribution

Understanding 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)
• GUI-based system administration tools
• Navigating virtual consoles
• Exiting the command prompt correctly
• Properly shutting down the system
• Restoring a functional console
• Recommended additional packages for beginners
• Setting up an extra user account
• Configuring sudo

Filesystem Management

• Understanding filesystem permissions
• Controlling permissions for new files using umask
• Managing permissions for user groups
• Working with timestamps
• Creating and using links
• Understanding named pipes (FIFOs)
• Working with sockets
• Managing device files
• Handling special device files
• Interacting with procfs and sysfs

Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Navigating the file manager within MC
• Advanced command-line techniques in MC
• Utilizing the built-in text editor
• Utilizing the built-in file viewer
• Configuring MC for automatic startup
• Using MC's FTP virtual filesystem

Basic Unix-like Work Environment

• Configuring the login shell
• Customizing bash
• Using special key combinations
• Utilizing the pager
• Setting a default text editor
• Navigating vim
• Logging shell activities
• Mastering basic Unix commands

Essential Shell Commands

• Command execution and environment variables
• Understanding the "$LANG" variable
• Understanding the "$PATH" variable
• Understanding the "$HOME" variable
• Utilizing command line options
• Using shell globbing
• Interpreting command return values
• Common command sequences and shell redirection
• Creating command aliases

Unix-like Text Processing

• Essential Unix text tools
• Working with 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

Package Management Prerequisites

• Configuring packages
• Essential precautions
• Managing continuous upgrades
• Understanding Debian archive basics
• Understanding package dependencies
• The lifecycle of package management events
• Initial troubleshooting for package management issues

Basic Package Management Operations

• Comparing apt-get/apt-cache vs. aptitude
• Performing basic package management via the command line
• Interactively using aptitude
• Navigating aptitude key bindings
• Exploring package views in aptitude
• Search method options in aptitude
• Understanding the aptitude regex syntax
• Resolving dependencies with aptitude
• Reviewing package activity logs

Aptitude Operation Examples

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

Advanced Package Management Operations

• Executing advanced package management commands
• Verifying installed package files
• Implementing safeguards for package issues
• Searching package metadata

Debian Package Management Internals

• Archive metadata structure
• The top-level "Release" file and authenticity verification
• Archive-level "Release" files
• Retrieving package metadata
• Package state management in APT
• Package state management in aptitude
• Managing local copies of fetched packages
• Debian package file naming conventions
• Using the dpkg command
• Using the update-alternatives command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

System Recovery

• Addressing incompatibility with legacy user configurations
• Handling overlapping files in different packages
• Fixing broken package scripts
• Rescuing the system using dpkg
• Recovering package selection data

Package Management Best Practices

• Selecting appropriate Debian packages
• Managing packages from mixed archive sources
• Adjusting candidate versions
• Understanding updates and backports
• Automating package download 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
• Recommended further reading 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 init scripts
• Configuring the hostname
• Filesystem initialization
• Initializing network interfaces
• Initializing network services
• System messages
• Kernel messages
• The udev system
• Initializing kernel modules

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
• 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
• Ensuring authentication security
• Secure password transmission over the Internet
• Using Secure Shell (SSH)
• Implementing extra security measures for the Internet
• Securing the root password

Network Configuration

Basic Network Infrastructure

• Understanding 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

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

Network Optimization

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

Netfilter Infrastructure

Network Applications

Mail System

• Modern mail service fundamentals
• Mail configuration strategy 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 non-standard SSH clients
• Configuring ssh-agent
• Shutting down remote systems via SSH
• SSH troubleshooting

Other Network Application Servers

Other Network Application Clients

System Daemon Diagnosis

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 (traditional method)
• Customizing the X session (modern method)
• Connecting a remote X client 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
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repetitions
• Recording the graphical image of an X application
• Recording changes in configuration files

Data Storage Tips

• Disk partition configuration
• Accessing partitions using UUIDs
• Filesystem configuration
• Creating filesystems and performing integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblocks
• Hard disk optimization
• 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 processes
• Setting 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 program startup
• Killing a process
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Identifying logged-in users
• Sending warnings to all users
• Hardware identification
• Hardware configuration
• Setting system and hardware time
• Terminal configuration
• Sound infrastructure setup
• 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
• Managing 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
• Removable storage devices
• Sharing data via 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
• Managing invisible disk space consumption

Data Security Infrastructure

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