Debian Administration Training Course

Understanding Debian Distribution

What is Debian?

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

Console Essentials

• Understanding the shell prompt
• Navigating the shell prompt in an X environment
• Managing the root account and root shell prompt (utilizing su, sudo, and running programs as root under X)
• Utilizing GUI system administration tools
• Navigating virtual consoles
• Exiting the command prompt properly
• Safely shutting down the system
• Restoring a functional console state
• Recommended additional packages for beginners
• Creating an extra user account
• Configuring sudo permissions

Filesystem Fundamentals

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

Mastering Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Using the file manager within MC
• Applying command-line techniques in MC
• Utilizing MC’s internal editor
• Using MC’s internal viewer
• Enabling MC’s auto-start features
• Accessing the FTP virtual filesystem in MC

The Standard Unix-like Work Environment

• Working with the login shell
• Customizing bash configurations
• Using special keystrokes effectively
• Utilizing the pager
• Setting a default text editor
• Navigating vim to quit
• Logging shell activities
• Executing basic Unix commands

Basic Shell Commands

• Command execution and environment variables
• Using the "$LANG" variable
• Configuring the "$PATH" variable
• Understanding the "$HOME" variable
• Navigating command line options
• Using shell glob patterns
• Interpreting command return values
• Implementing typical command sequences and shell redirection
• Creating command aliases

Unix-like Text Processing

• Utilizing Unix text tools
• Working with regular expressions
• Applying replacement expressions
• Performing global substitution with regular expressions
• Extracting data from text file tables
• Writing script snippets for piping commands

Debian Package Management

Prerequisites for Package Management

• Package configuration strategies
• Essential precautions to take
• Managing ongoing upgrades
• Understanding Debian archive structures
• Handling package dependencies
• Understanding the package management event flow
• Initial troubleshooting for package management issues

Basic Package Management Operations

• Comparing apt-get/apt-cache with aptitude
• Executing basic package management operations via the command line
• Interactively using aptitude
• Utilizing aptitude key bindings
• Navigating package views in aptitude
• Configuring search method options in aptitude
• Applying aptitude regex patterns
• 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
• Managing auto/manual installation status
• Performing system-wide upgrades

Advanced Package Management Operations

• Executing advanced package management operations via the command line
• Verifying installed package files
• Implementing safeguards for package issues
• Searching package metadata

Internals of Debian Package Management

• Archive metadata structures
• The top-level "Release" file and its authenticity
• Archive-level "Release" files
• Fetching package metadata
• APT package states
• aptitude package states
• Local copies of fetched packages
• Debian package naming conventions
• Using the dpkg command
• Managing alternatives with update-alternative
• Using dpkg-statoverride
• Managing diversions with dpkg-divert

Recovering from a Broken System

• Addressing incompatibility with old user configurations
• Handling overlapping files in different packages
• Fixing broken package scripts
• Using dpkg for rescue operations
• Recovering package selection data

Package Management Tips

• Selecting appropriate Debian packages
• Handling packages from mixed archive sources
• Adjusting candidate versions
• Managing updates and backports
• Automating package downloads and upgrades
• Limiting APT download bandwidth
• Executing emergency downgrades
• Identifying package uploaders
• Utilizing the equivs package
• Porting packages to stable systems
• Configuring APT proxy servers
• Creating 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 process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Managing the hostname
• Filesystem initialization
• Initializing network interfaces
• Initializing network services
• Understanding system messages
• Interpreting kernel messages
• Managing 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
• Understanding GNU su and the wheel group
• Enforcing stricter password rules
• Implementing additional access controls
• Configuring sudo
• Utilizing SELinux and AppArmor
• Restricting access to specific server services
• Ensuring authentication security
• Sending passwords securely over the Internet
• Securing Shell connections
• Implementing extra security measures for Internet services
• Securing the root password

Network Configuration

Basic Network Infrastructure

• Managing domain names
• Configuring hostname resolution
• Understanding network interface naming
• Defining LAN network address ranges
• Configuring network device support

Modern Network Configuration for Desktops

• Using GUI network configuration tools

Low-Level Network Configuration

• Using iproute2 commands
• Safely performing low-level network operations

Network Optimization

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

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 usage with 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
• Handling incompatible SSH clients
• Setting up 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
• Understanding the server/client relationship
• Configuring the X server
• Starting the X Window System
• Starting X sessions with gdm
• Customizing X sessions (classic method)
• Customizing X sessions (new method)
• Connecting remote X clients via SSH
• Securing X terminals over the Internet
• Utilizing X applications
• Using X office applications
• Using X utility applications

System Tips

The Screen Program

• Use cases for screen(1)
• Key bindings for the screen command

Data Recording and Presentation

• Using the log daemon
• Utilizing log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Colorized shell echo commands
• Colorized command outputs
• Recording editor activities for complex repetitions
• Recording graphical images of X applications
• Recording changes in configuration files

Data Storage Tips

• Disk partition configuration
• Accessing partitions using UUID
• Filesystem configuration
• Creating filesystems and performing integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock
• Hard disk optimization
• Using SMART to predict hard disk failures
• Expanding usable storage 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
• Creating encrypted swap partitions with dm-crypt
• Automatically encrypting files with eCryptfs
• Automatically mounting eCryptfs

Monitoring, Controlling, and Starting Program Activities

• Timing process duration
• 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
• Looping commands over files
• Starting programs from the GUI
• Customizing startup programs
• Killing processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Checking who is logged into the system
• Broadcasting warnings to all users
• Identifying hardware
• Configuring hardware
• Synchronizing system and hardware time
• Configuring terminals
• Managing sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• Performing system security and integrity checks

The Kernel

• Configuring kernel parameters
• Managing kernel headers
• Compiling the kernel and related modules
• Compiling kernel source: Debian standard method
• Compiling module source: Debian standard method
• Managing non-free hardware drivers

Virtualized Systems

• Using virtualization tools
• Understanding virtualization workflows
• Mounting virtual disk image files
• Setting up Chroot systems
• Managing multiple desktop systems

Data Management

Sharing, Copying, and Archiving

• Archive and compression tools
• Copy and synchronization tools
• Idioms for archiving
• Idioms for copying
• Idioms for file selection
• Backup and recovery strategies
• Backup utility suites
• Example script for system backup
• Script for data backup copying
• Managing removable storage devices
• Sharing data via network
• Archive media options

Binary Data

• Viewing and editing binary data
• Manipulating files without mounting disks
• Understanding data redundancy
• Data file 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
• Undeleting deleted but still open files
• Searching for all hardlinks
• Identifying invisible disk space consumption

Data Security Infrastructure

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