Debian Administration Training Course

Debian Distribution

What is Debian?

• Choosing a Debian version
• Debian support and help
• Debian community engagement

Console Basics

• The shell prompt
• The shell prompt under X
• The root account and root shell prompt (su, sudo, running programs as root under X)
• GUI system administration tools
• Virtual consoles
• Exiting the command prompt
• Shutting down the system
• Recovering a functional console
• Additional package suggestions for new users
• Creating an extra user account
• Configuring sudo

The Filesystem

• Filesystem permissions
• Control of permissions for newly created files: umask
• Permissions for groups of users (group)
• Timestamps
• Links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• procfs and sysfs

Midnight Commander (MC)

• Customizing MC for government use
• Starting MC
• Using the file manager in MC
• Command-line tricks in MC
• The internal editor in MC
• The internal viewer in MC
• Auto-start features of MC
• FTP virtual filesystem of MC

The Basic Unix-like Work Environment

• The login shell for government systems
• Customizing bash for enhanced security
• Special key strokes for efficient navigation
• The pager for document viewing
• Setting a default text editor for consistency
• Exiting vim securely
• Recording the shell activities for audit purposes
• Basic Unix commands for system management

The Simple Shell Command

• Command execution and environment variables in government systems
• The "$LANG" variable for language settings
• The "$PATH" variable for command search paths
• The "$HOME" variable for user directories
• Command line options for customization
• Shell globbing for file pattern matching
• Return value of the command for error handling
• Typical command sequences and shell redirection for workflow automation
• Command aliasing for efficiency

Unix-like Text Processing

• Unix text tools for data manipulation
• Regular expressions for pattern matching
• Replacement expressions for data transformation
• Global substitution with regular expressions for bulk changes
• Extracting data from text file tables for reporting
• Script snippets for piping commands for complex operations

Debian Package Management

Debian Package Management Prerequisites

• Package configuration for government systems
• Basic precautions to ensure system integrity
• Life with eternal upgrades and security updates
• Basics of the Debian archive structure
• Understanding package dependencies for seamless integration
• The event flow of the package management process
• First response to package management issues for quick resolution

Basic Package Management Operations

• Using apt-get/apt-cache vs. aptitude for government systems
• Basic package management operations with the command line for efficiency
• Interactive use of aptitude for detailed control
• Key bindings of aptitude for faster navigation
• Package views under aptitude for organized management
• Search method options with aptitude for precise queries
• The aptitude regex formula for advanced searches
• Dependency resolution of aptitude for conflict-free installations
• Package activity logs for audit trails

Examples of Aptitude Operations

• Listing packages with regex matching on package names for targeted actions
• Browsing with the regex matching for efficient exploration
• Purging removed packages to free up space
• Tidying auto/manual install status for cleaner system management
• System-wide upgrades for security and functionality updates

Advanced Package Management Operations

• Advanced package management operations with the command line for complex tasks
• Verification of installed package files for integrity checks
• Safeguarding against package problems for system stability
• Searching on the package metadata for detailed information

Debian Package Management Internals

• Archive metadata for transparent operations
• The top-level "Release" file and authenticity verification for security
• Archive-level "Release" files for comprehensive data
• Fetching of the metadata for the package for up-to-date information
• The package state for APT for tracking installations
• The package state for aptitude for detailed management
• Local copies of the fetched packages for offline access
• Debian package file names for easy identification
• The dpkg command for low-level operations
• The update-alternative command for managing alternatives
• The dpkg-statoverride command for special permissions
• The dpkg-divert command for redirection

Recovery from a Broken System

• Incompatibility with old user configuration and resolution strategies
• Different packages with overlapping files and conflict resolution
• Fixing broken package scripts for system repairs
• Rescue operations with the dpkg command for critical fixes
• Recovering package selection data for system restoration

Tips for Package Management

• How to pick Debian packages for government systems
• Packages from mixed sources of archives for diverse needs
• Tweaking candidate version for specific requirements
• Updates and Backports for staying current
• Automatic download and upgrade of packages for streamlined maintenance
• Limiting download bandwidth for APT to manage resources
• Emergency downgrading for critical situations
• Identifying who uploaded the package for accountability
• The equivs package for creating virtual dependencies
• Porting a package to the stable system for compatibility
• Proxy server for APT for secure access
• Small public package archive for specialized needs
• Recording and copying system configuration for backups
• Converting or installing an alien binary package for flexibility
• Extracting a package without dpkg for quick access
• Further readings for in-depth knowledge of package management

The System Initialization

• An overview of the boot process for government systems
• BIOS, boot loader, and mini-Debian system initialization
• The meaning of runlevels for system states
• The configuration of runlevels for customized operations
• A runlevel management example for practical application
• The default parameter for each init script for consistent behavior
• Setting the hostname for identification
• Configuring the filesystem for optimal performance
• Network interface initialization for connectivity
• Network service initialization for functionality
• The system message logs for monitoring
• The kernel message logs for low-level insights
• The udev system for device management
• The kernel module initialization for hardware support

Authentication and Security

• Normal Unix authentication for secure access
• Managing account and password information for user management
• Good password practices for enhanced security
• Creating encrypted passwords for secure storage
• PAM (Pluggable Authentication Modules) and NSS (Name Service Switch) for flexible authentication
• Configuration files accessed by PAM and NSS for system integration
• The modern centralized system management for scalability
• Understanding why GNU su does not support the wheel group for security reasons
• Stricter password rules for enhanced protection
• Other access controls for comprehensive security
• Using sudo for privilege escalation
• SELinux and Apparmor for advanced security policies
• Restricting access to server services for controlled environments
• Security of authentication mechanisms for government systems
• Secure password transmission over the Internet for remote access
• Secure Shell (SSH) for encrypted connections
• Extra security measures for Internet-facing systems for government use
• Securing the root password for administrative accounts

Network Setup

The Basic Network Infrastructure

• The domain name system (DNS) for network identification
• The hostname resolution for accessible communication
• The network interface naming conventions for clarity
• The network address range for local area networks (LANs)
• Network device support for hardware compatibility

The Modern Network Configuration for Desktops

• GUI network configuration tools for user-friendly setup

The Low-Level Network Configuration

• Iproute2 commands for advanced networking
• Safe low-level network operations for system stability

Network Optimization

• Finding the optimal Maximum Transmission Unit (MTU) for performance
• Setting the MTU for network efficiency
• WAN TCP optimization for long-distance communication

Netfilter Infrastructure

Network Applications

The Mail System

• Basics of modern mail services for government operations
• A mail configuration strategy for workstations for streamlined communications

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

• An overview of exim4 for efficient mail transport
• Basic MUA - Mutt for user-friendly email management

Mail Delivery Agent (MDA) with Filter

• Configuring maildrop for filtered delivery
• Configuring procmail for advanced filtering
• Redelivering mbox contents for backup and archiving

POP3/IMAP4 Server

The Remote Access Server and Utility (SSH)

• Basics of SSH for secure remote access
• Port forwarding for SMTP/POP3 tunneling for encrypted communication
• Connecting without remote passwords for convenience
• Dealing with alien SSH clients for compatibility
• Setting up ssh-agent for key management
• Shutting down the remote system on SSH for administrative tasks
• Troubleshooting SSH for problem resolution

Other Network Application Servers

Other Network Application Clients

The Diagnosis of System Daemons

The X Window System

• Setting up a desktop environment for government use
• The server/client relationship in the X Window System
• The X server for graphical display
• Starting the X Window System for user access
• Starting an X session with gdm for secure logins
• Customizing the X session (classic method) for tailored experiences
• Customizing the X session (new method) for modern configurations
• Connecting a remote X client via SSH for secure access
• Secure X terminal via the Internet for remote work
• X applications for productivity
• X office applications for document management
• X utility applications for system tools

System Tips

The Screen Program

• Use scenarios for screen(1) for enhanced terminal sessions
• Key bindings for the screen command for efficient navigation

Data Recording and Presentation

• The log daemon for system logging
• Log analyzers for detailed insights
• Recording shell activities cleanly for audit purposes
• Customized display of text data for readability
• Customized display of time and date for clarity
• Colorized shell echo for visual differentiation
• Colorized commands for enhanced visibility
• Recording editor activities for complex repeats
• Recording the graphic image of an X application for documentation
• Recording changes in configuration files for version control

Data Storage Tips

• Disk partition configuration for optimal use
• Accessing partitions using UUID for consistent identification
• Filesystem configuration for performance and reliability
• Creating and checking filesystem integrity for data protection
• Optimizing the filesystem with mount options for enhanced performance
• Optimizing the filesystem via superblock settings for advanced tuning
• Optimizing hard disk operations for improved efficiency
• Using SMART to predict hard disk failures for proactive maintenance
• Expanding usable storage space via Logical Volume Management (LVM)
• Expanding usable storage space by mounting another partition for additional capacity
• Expanding usable storage space using symbolic links for flexible access
• Expanding usable storage space using aufs for layered filesystems

Data Encryption Tips

• Encrypting removable disks with dm-crypt/LUKS for secure data transport
• Encrypting swap partitions with dm-crypt for enhanced security
• Automatically encrypting files with eCryptfs for transparent encryption
• Automatically mounting eCryptfs for seamless access

Monitoring, Controlling, and Starting Program Activities

• Timing a process for performance analysis
• The scheduling priority for resource management
• The ps command for process monitoring
• The top command for real-time system monitoring
• Listing files opened by a process for diagnostic purposes
• Tracing program activities for debugging
• Identifying processes using files or sockets for security checks
• Repeating a command with a constant interval for periodic tasks
• Repeating a command looping over files for batch processing
• Starting a program from the GUI for user-friendly access
• Customizing programs to be started for tailored configurations
• Killing a process for system maintenance
• Scheduling tasks once for one-time operations
• Scheduling tasks regularly for automated maintenance
• Using the Alt-SysRq key for emergency system management

System Maintenance Tips

• Determining who is on the system for user tracking
• Warning everyone before system changes for communication
• Identifying hardware components for system configuration
• Configuring hardware settings for optimal performance
• Managing system and hardware time for synchronization
• Configuring terminal settings for user preferences
• Setting up the sound infrastructure for multimedia applications
• Disabling the screen saver for continuous operation
• Disabling beep sounds for a quiet environment
• Monitoring memory usage for system health
• Conducting system security and integrity checks for compliance

The Kernel

• Kernel parameters for performance tuning
• Kernel headers for module development
• Compiling the kernel and related modules for customized systems
• Compiling the kernel source using the Debian standard method for consistency
• Compiling the module source using the Debian standard method for integration
• Managing non-free hardware drivers for specialized needs

Virtualized System

• Virtualization tools for efficient resource utilization
• The virtualization workflow for deployment and management
• Mounting the virtual disk image file for data access
• Using chroot for isolated environments
• Managing multiple desktop systems for user convenience

Data Management

Sharing, Copying, and Archiving

• Archive and compression tools for efficient storage
• Copy and synchronization tools for data integrity
• Idioms for the archive for consistent practices
• Idioms for the copy for reliable operations
• Idioms for selecting files for targeted actions
• Backup and recovery strategies for data protection
• Backup utility suites for comprehensive solutions
• An example script for system backup for government use
• A copy script for data backup for regular maintenance
• Removable storage devices for portable backups
• Sharing data via network for collaborative work
• Archive media for long-term storage

The Binary Data

• Viewing and editing binary data for specialized tasks
• Manipulating files without mounting disk for direct access
• Data redundancy strategies for reliability
• Data file recovery and forensic analysis for incident response
• Splitting a large file into smaller files for easier management
• Clearing file contents for secure deletion
• Creating dummy files for testing purposes
• Erasing an entire hard disk for secure disposal
• Erasing unused areas of a hard disk for data sanitization
• Undeleting deleted but still open files for recovery
• Searching all hardlinks for file management
• Invisible disk space consumption and its causes for system optimization

Data Security Infrastructure

• Key management for GnuPG (signing and encrypting) for secure communications
• The MD5 sum for data integrity verification