Debian Administration Training Course

Debian Distribution

Introduction to Debian

• Selecting a Debian version
• Debian support and assistance resources
• Overview of the Debian community

Console Fundamentals

• Understanding the shell prompt
• Using the shell prompt within the X environment
• Managing the root account and root shell prompt (su, sudo, executing programs as root under X)
• GUI-based system administration tools
• Navigating virtual consoles
• Exiting the command prompt
• Procedures for shutting down the system
• Restoring a stable console state
• Recommended additional packages for beginners
• Creating additional user accounts
• Configuring sudo

The Filesystem

• Filesystem permission structures
• Controlling permissions for newly created files via umask
• Managing permissions for user groups
• Working with timestamps
• Understanding links
• Utilizing Named pipes (FIFOs)
• Working with sockets
• Device files
• Special device files
• procfs and sysfs concepts

Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Using the file manager within MC
• Advanced command-line techniques in MC
• Using the internal editor in MC
• Utilizing the internal viewer in MC
• MC auto-start capabilities
• Accessing the FTP virtual filesystem via MC

The Basic Unix-like Working Environment

• Understanding the login shell
• Customizing bash configurations
• Using special key combinations
• Utilizing the pager
• Configuring a default text editor
• Exiting vim effectively
• Recording shell activities
• Essential Unix commands

Simple Shell Commands

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

Unix-like Text Processing

• Essential 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 basics
• Essential precautions
• Managing systems with continuous upgrades
• Debian archive fundamentals
• Understanding package dependencies
• The workflow of package management events
• Initial responses to package management issues

Basic Package Management Operations

• Comparing apt-get/apt-cache with aptitude
• Performing basic package management via the command line
• Interactive usage of aptitude
• Key bindings in aptitude
• Viewing packages in aptitude
• Search options in aptitude
• Using aptitude regex formulas
• Dependency resolution in aptitude
• Reviewing package activity logs

aptitude Operation Examples

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

Advanced Package Management Operations

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

Internals of Debian Package Management

• Archive metadata structures
• The top-level "Release" file and authenticity verification
• Archive-level "Release" files
• Retrieving package metadata
• Package states in APT
• Package states in aptitude
• Local copies of downloaded packages
• Debian package file naming conventions
• Using the dpkg command
• Using the update-alternative command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

Recovering from a Broken System

• Addressing incompatibilities with old user configurations
• Resolving file overlaps between different packages
• Fixing broken package scripts
• Rescuing the system using the dpkg command
• Restoring package selection data

Package Management Tips

• Selecting appropriate Debian packages
• Handling packages from mixed archive sources
• Adjusting candidate versions
• Working with Updates and Backports
• Automating package downloads and upgrades
• Limiting APT download bandwidth
• Performing emergency downgrades
• Identifying package uploaders
• Using the equivs package
• Porting packages to stable systems
• Configuring a proxy server for APT
• Setting up small public package archives
• Recording and duplicating system configurations
• Converting or installing foreign binary packages
• Extracting packages without dpkg
• Further reading on package management

System Initialization

• Overview of the boot strap process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Example of runlevel management
• Default parameters for init scripts
• Configuring the hostname
• Filesystem mounting during initialization
• Initializing network interfaces
• Initializing network services
• System messages
• Kernel messages
• The udev system
• Kernel module initialization

Authentication and Security

• Standard Unix authentication mechanisms
• 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 management
• Why GNU su does not support the wheel group
• Enforcing stricter password policies
• Additional access control methods
• Using sudo
• Implementing SELinux and Apparmor
• Restricting access to specific server services
• Securing authentication processes
• Transmitting passwords securely over the internet
• Utilizing Secure Shell (SSH)
• Additional internet security measures
• Protecting the root password

Network Setup

Basic Network Infrastructure

• Domain names
• Hostname resolution
• Naming network interfaces
• Defining LAN network address ranges
• Network device support

Modern Desktop Network Configuration

• Using GUI-based network configuration tools

Low-Level Network Configuration

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

Network Optimization

• Determining the optimal MTU
• Setting the MTU
• Optimizing TCP for WAN connections

Netfilter Infrastructure

Network Applications

The Mail System

• Fundamentals of modern mail services
• Mail configuration strategies for workstations

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

• Overview of exim4
• Basics of MUA - 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 external SSH clients
• Setting up ssh-agent
• Shutting down remote systems via SSH
• Troubleshooting SSH connections

Other Network Application Servers

Other Network Application Clients

Diagnosing System Daemons

The X Window System

• Setting up the desktop environment
• Understanding server/client relationships
• The X server role
• Launching the X Window System
• Starting X sessions via gdm
• Customizing X sessions (traditional methods)
• Customizing X sessions (modern methods)
• Connecting remote X clients via SSH
• Securing X terminals over the internet
• Overview of 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

• Using the log daemon
• Employing log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Using colorized shell echo
• Colorizing commands
• Recording editor activities for complex repetitions
• Capturing graphic images of X applications
• Tracking changes in configuration files

Data Storage Tips

• Disk partition configuration
• Accessing partitions using UUIDs
• Filesystem configuration
• Creating filesystems and running integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblocks
• Hard disk optimization
• Predicting hard disk failures using SMART
• Expanding usable storage space with LVM
• Expanding usable storage space by mounting additional partitions
• Expanding usable storage space using symbolic links
• 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 using eCryptfs
• Automatically mounting eCryptfs volumes

Monitoring, Controlling, and Starting Program Activities

• Timing processes
• Managing scheduling priority
• 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 constant intervals
• Looping commands over file sets
• Starting programs from the GUI
• Customizing program startup configurations
• Terminating processes
• Scheduling one-time tasks
• Scheduling regular tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Identifying active users on the system
• Broadcasting warnings to all users
• Hardware identification
• Hardware configuration
• Managing system and hardware time
• Terminal configuration
• Sound infrastructure
• Disabling screen savers
• 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 using Debian standard methods
• Compiling module source using Debian standard methods
• Handling non-free hardware drivers

Virtualized Systems

• Virtualization tools
• Virtualization workflows
• Mounting virtual disk image files
• Using chroot systems
• Managing multiple desktop systems

Data Management

Sharing, Copying, and Archiving

• Archive and compression utilities
• Copy and synchronization tools
• Common idioms for archiving
• Common idioms for copying
• Idioms for file selection
• Backup and recovery procedures
• Backup utility suites
• Example scripts for system backup
• Scripts for data backup copying
• Working with removable storage devices
• Sharing data over the network
• Archive media management

Binary Data

• Viewing and editing binary data
• Manipulating files without mounting disks
• Managing data redundancy
• Data file recovery and forensic analysis
• Splitting large files into smaller segments
• Clearing file contents
• Working with dummy files
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Undeleting files that are deleted but still open
• Searching for all hard links
• Identifying invisible disk space consumption

Data Security Infrastructure

• GnuPG key management for signing and encryption
• Using MD5 sums