Debian Administration Training Course

Debian Distribution

Understanding Debian

• Selecting the appropriate Debian version
• Debian support and resources for assistance
• The Debian community

Fundamentals of the Console

• 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 in X)
• GUI-based system administration utilities
• Navigating virtual consoles
• Exiting the command prompt properly
• Properly shutting down the system
• Restoring a functional console state
• Recommended additional packages for beginners
• Creating an additional user account
• Configuring sudo

Filesystem Management

• Filesystem permissions
• Controlling permissions for newly created files: umask
• Managing permissions for user groups (group)
• Understanding timestamps
• Working with links
• Named pipes (FIFOs)
• Network sockets
• Device files
• Special device files
• Understanding procfs and sysfs

Mastering Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Navigating the file manager within MC
• Advanced command-line techniques in MC
• Utilizing the built-in editor in MC
• Utilizing the built-in viewer in MC
• MC auto-start features
• MC's FTP virtual filesystem capabilities

The Standard Unix-like Work Environment

• The login shell
• Customizing bash
• Utilizing special key strokes
• Using the pager
• Setting a default text editor
• Exiting vim effectively
• Recording shell activity logs
• Essential Unix commands

Basic Shell Commands

• Command execution and environment variables
• The "$LANG" variable
• The "$PATH" variable
• The "$HOME" variable
• Command line options
• Shell globbing
• Command return values
• Typical command sequences and shell redirection
• Setting command aliases

Unix-like Text Processing

• Essential Unix text tools
• Regular expressions
• Replacement expressions
• Performing global substitutions with regular expressions
• Extracting data from text file tables
• Script snippets for piping commands

Debian Package Management

Prerequisites for Package Management

• Package configuration basics
• Essential precautions to take
• Navigating the cycle of continuous upgrades
• Foundations of the Debian archive
• Understanding package dependencies
• The lifecycle of package management operations
• Initial responses to package management issues

Core Package Management Operations

• Comparing apt-get/apt-cache vs. aptitude
• Executing basic package management operations via the command line
• Interactive usage of aptitude
• Key bindings within aptitude
• Navigating package views in aptitude
• Search method options in aptitude
• Utilizing the aptitude regex formula
• Dependency resolution in aptitude
• Reviewing package activity logs

Practical Examples of aptitude Operations

• Listing packages using regex matching on package names
• Browsing packages with regex matching
• Completely purging removed packages
• Managing auto/manual installation status
• Performing a system-wide upgrade

Advanced Package Management Operations

• Executing advanced package management tasks via the command line
• Verifying installed package files
• Strategies for safeguarding against package issues
• Searching within package metadata

Internals of Debian Package Management

• Archive metadata structure
• The top-level "Release" file and authenticity verification
• Archive-level "Release" files
• Fetching metadata for packages
• Package states in APT
• Package states in aptitude
• Local caching of fetched packages
• Debian package file naming conventions
• Utilizing the dpkg command
• Using the update-alternative command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

Recovering from a Broken System

• Handling incompatibilities with old user configurations
• Managing different packages with overlapping files
• Repairing broken package scripts
• Rescuing systems using the dpkg command
• Restoring package selection data

Tips for Effective Package Management

• Selecting appropriate Debian packages
• Handling packages from mixed archive sources
• Tweaking candidate versions
• Understanding Updates and Backports
• Automating package downloads and upgrades
• Limiting download bandwidth for APT
• Emergency downgrading procedures
• Identifying the package uploader
• Utilizing the equivs package
• Porting packages to the stable system
• Configuring a proxy server for APT
• Managing a small public package archive
• Recording and copying system configuration
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Further reading for package management

System Initialization

• Overview of the boot strap process
• BIOS, boot loader, and the mini-Debian system
• Understanding runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Setting the hostname
• Filesystem mounting
• Network interface initialization
• Network service initialization
• System messages
• Kernel messages
• The udev system
• Kernel module initialization

Authentication and Security

• Standard Unix authentication methods
• Managing account and password information
• Establishing strong passwords
• Creating 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
• Other access control mechanisms
• Using sudo
• SELinux and Apparmor
• Restricting access to specific server services
• Ensuring authentication security
• Transmitting secure passwords over the Internet
• Secure Shell (SSH)
• Additional security measures for Internet usage
• Securing the root password

Network Setup

Basic Network Infrastructure

• Domain names
• Hostname resolution
• Network interface naming
• LAN network address ranges
• Network device support

Modern Network Configuration for Desktop

• GUI network configuration tools

Low-Level Network Configuration

• Using Iproute2 commands
• Safe low-level network operations

Network Optimization

• Identifying the optimal MTU
• Setting the MTU
• WAN TCP optimization

Netfilter Infrastructure

Network Applications

The Mail System

• 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 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
• SSH troubleshooting

Other Network Application Servers

Other Network Application Clients

Diagnosing System Daemons

The X Window System

• Setting up the desktop environment
• The server/client relationship
• 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
• Customized text data display
• Customized display of time and date
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repetitions
• Recording the graphic image of an X application
• 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 failure
• Expanding usable storage space via LVM
• Expanding usable storage space by mounting another partition
• 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 a process
• Setting 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 looping over files
• Starting a program from the GUI
• Customizing programs to be started
• Killing a process
• Scheduling tasks once
• Scheduling tasks regularly
• Using the Alt-SysRq key

System Maintenance Tips

• Identifying who is on the system
• Broadcasting warnings to everyone
• Hardware identification
• Hardware configuration
• System and hardware time
• Terminal configuration
• The 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 the module source: Debian standard method
• Non-free hardware drivers

Virtualized Systems

• Virtualization tools
• Virtualization workflow
• Mounting virtual disk image files
• 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
• Backup utility suites
• Example script for system backup
• Script for data backup
• Removable storage devices
• Sharing data via 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 deleted but still open files
• Searching for all hardlinks
• Identifying invisible disk space consumption

Data Security Infrastructure

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