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

• Navigating the shell prompt
• Managing the shell prompt within the X environment
• Utilizing the root account and root shell prompt (su, sudo, running programs as root under X)
• Employing GUI system administration tools
• Utilizing virtual consoles
• Exiting the command prompt
• Shutting down the system
• Restoring a functional console
• Recommended packages for beginners
• Setting up an additional user account
• Configuring sudo

Understanding the Filesystem

• Filesystem permissions
• Controlling permissions for new files: umask
• Permissions for user groups
• Managing timestamps
• Working with links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• Using procfs and sysfs

Mastering Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Utilizing the file manager within MC
• Employing command-line tricks in MC
• Using the internal editor in MC
• Using the internal viewer in MC
• Configuring MC auto-start features
• Utilizing MC's FTP virtual filesystem

The Basic Unix-like Work Environment

• Working with the login shell
• Customizing bash
• Using special key strokes
• Utilizing the pager
• Setting a default text editor
• Navigating out of vim
• Recording shell activities
• Executing 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
• Implementing typical command sequences and shell redirection
• Creating command aliases

Text Processing in Unix-like Systems

• Utilizing Unix text tools
• Understanding regular expressions
• Using 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 Debian Package Management

• Package configuration
• Essential precautions
• Managing continuous upgrades
• Understanding Debian archive basics
• Handling package dependencies
• Understanding the workflow of package management
• Addressing initial package management issues

Basic Package Management Operations

• Comparing apt-get/apt-cache with aptitude
• Performing basic package management operations via the command line
• Using aptitude interactively
• Navigating aptitude key bindings
• Viewing package statuses under aptitude
• Search method options with aptitude
• Applying the aptitude regex formula
• Resolving dependencies with aptitude
• Reviewing package activity logs

Examples of aptitude Operations

• Listing packages using regex matching on names
• Browsing packages with regex matching
• Permanently purging removed packages
• Cleaning up auto/manual install statuses
• Performing a system-wide upgrade

Advanced Package Management Operations

• Performing advanced package management operations via the command line
• Verifying installed package files
• Preventing package issues
• Searching package metadata

Internals of Debian Package Management

• Understanding archive metadata
• Verifying the top-level "Release" file and authenticity
• Examining archive-level "Release" files
• Fetching package metadata
• Managing package states for APT
• Managing package states for aptitude
• Maintaining local copies of fetched packages
• Understanding 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

• Handling incompatibility with old user configurations
• Resolving overlapping files from different packages
• Fixing broken package scripts
• Rescuing the system using dpkg
• Recovering package selection data

Tips for Package Management

• Selecting Debian packages
• Handling packages from mixed archive sources
• Adjusting candidate versions
• Utilizing updates and Backports
• Automating package download and upgrades
• Limited download bandwidth for APT
• Emergency downgrading procedures
• Identifying package uploaders
• Using the equivs package
• Porting packages to stable systems
• Configuring an APT proxy server
• Managing small public package archives
• Recording and copying system configurations
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Further resources for 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
• Managing the hostname
• Filesystem initialization
• Network interface initialization
• Network service initialization
• Handling system messages
• Handling kernel messages
• The udev system
• Kernel module initialization

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 why GNU su does not support the wheel group
• Implementing stricter password rules
• Implementing other access controls
• Using sudo
• Understanding SELinux and Apparmor
• Restricting access to certain server services
• Ensuring authentication security
• Securing passwords over the Internet
• Using Secure Shell
• 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 Network Configuration for Desktops

• Using GUI network configuration tools

Low-Level Network Configuration

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

Network Optimization

• Finding optimal MTU
• Setting MTU
• WAN TCP optimization

Netfilter Infrastructure

Network Applications

The Mail System

• Basics of modern mail services
• 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 Servers and Utilities (SSH)

• SSH fundamentals
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Managing incompatible SSH clients
• Setting up ssh-agent
• Shutting down remote systems via SSH
• Troubleshooting SSH

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
• Managing the X server
• Starting the X Window System
• Starting an X session with gdm
• Customizing the X session (classic method)
• Customizing the X session (new 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 repeats
• Recording graphic images of X applications
• Recording changes in configuration files

Data Storage Tips

• Disk partition configuration
• Accessing partitions using UUID
• Filesystem configuration
• Filesystem creation and integrity checks
• Filesystem optimization via mount options
• Filesystem optimization via superblock
• Hard disk optimization
• Using SMART to predict hard disk failures
• Expanding storage space via LVM
• Expanding storage space by mounting another partition
• Expanding storage space using symlinks
• 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
• Automounting eCryptfs

Monitoring, Controlling, and Starting Program Activities

• Timing a process
• Managing scheduling priority
• Using the ps command
• Using the top command
• Listing files opened by a process
• Tracing program activities
• Identifying processes using files or sockets
• Repeating a command at constant intervals
• Repeating a command over files
• Starting a program from the GUI
• Customizing startup programs
• Killing a process
• Scheduling one-off tasks
• Scheduling regular tasks
• Using the Alt-SysRq key

System Maintenance Tips

• Identifying logged-in users
• Notifying all users
• Hardware identification
• Hardware configuration
• Setting system and hardware time
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• System security and integrity checks

The Kernel

• Kernel parameters
• Kernel headers
• Compiling the kernel and related modules
• Compiling the 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
• Chroot systems
• Multiple desktop systems

Data Management

Sharing, Copying, and Archiving

• Archive and compression tools
• Copy and synchronization tools
• Idioms for archives
• Idioms for copying
• Idioms for file selection
• Backup and recovery
• Backup utility suites
• Example script for system backup
• Script for data backup
• Removable storage devices
• Sharing data via the network
• Archive media

Binary Data

• Viewing and editing binary data
• Manipulating files without mounting the disk
• 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 files that are deleted but still open
• Searching for all hard links
• Identifying invisible disk space consumption

Data Security Infrastructure

• Key management for GnuPG (signing and encrypting)
• Understanding the MD5 sum