Debian Administration Training Course

Debian Distribution

Introduction to Debian

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

Console fundamentals

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

Filesystem structure

• Understanding filesystem permissions
• Controlling permissions for new files using umask
• Managing group-based permissions
• Working with timestamps
• Creating and using symbolic and hard links
• Utilizing named pipes (FIFOs)
• Working with sockets
• Understanding device files
• Handling special device files
• Interacting with procfs and sysfs

Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Using the file manager within MC
• Applying command-line shortcuts in MC
• Using the integrated editor in MC
• Using the integrated viewer in MC
• Configuring auto-start features in MC
• Accessing the FTP virtual filesystem via MC

Basic Unix-like working environment

• Understanding the login shell
• Customizing bash behavior
• Using special key combinations
• Utilizing the pager utility
• Setting a default text editor
• Exiting vim correctly
• Recording shell session activities
• Essential Unix commands

Basic shell command execution

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

Unix-like text processing

• Standard Unix text tools
• Using regular expressions
• Working with replacement expressions
• Performing global substitutions with regex
• Extracting data from text file tables
• Script snippets for piping commands

Debian package management

Prerequisites for Debian package management

• Package configuration basics
• Essential safety precautions
• Managing continuous system upgrades
• Fundamentals of the Debian archive
• Understanding package dependencies
• The workflow of package management events
• Initial steps for resolving package management issues

Core package management operations

• Comparing apt-get/apt-cache with aptitude
• Performing basic package operations via the command line
• Using aptitude interactively
• Applying key bindings in aptitude
• Viewing packages using aptitude views
• Using search options in aptitude
• Understanding aptitude regex formulas
• Resolving dependencies with aptitude
• Reviewing package activity logs

Practical aptitude operations

• Listing packages using regex matching on names
• Browsing packages with regex filters
• Thoroughly purging removed packages
• Organizing auto-installed vs. manually installed status
• Performing system-wide upgrades

Advanced package management operations

• Executing advanced package operations from the command line
• Verifying installed package files
• Implementing safeguards against package issues
• Searching package metadata

Internals of Debian package management

• Understanding archive metadata
• Top-level "Release" files and authenticity checks
• Archive-level "Release" files
• Retrieving package metadata
• Package state tracking in APT
• Package state tracking in aptitude
• Managing local copies of fetched packages
• Naming conventions for Debian package files
• Using the dpkg command
• Using the update-alternatives command
• Using the dpkg-statoverride command
• Using the dpkg-divert command

Recovering from a broken system

• Resolving incompatibilities with old user configurations
• Handling packages with overlapping file ownership
• Fixing broken package scripts
• Using dpkg for rescue operations
• Restoring package selection data

Package management best practices

• Strategies for selecting Debian packages
• Managing packages from mixed archive sources
• Adjusting candidate versions
• Managing 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 proxy servers for APT
• Setting up small public package archives
• Recording and copying system configurations
• Converting or installing alien binary packages
• Extracting packages without using dpkg
• Further reading on package management

System initialization

• Overview of the bootstrapping process
• BIOS, boot loaders, and mini-Debian systems
• The concept of runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Setting the hostname
• Filesystem mounting during boot
• Initializing network interfaces
• Starting network services
• Managing system messages
• Reviewing kernel messages
• The udev subsystem
• Initializing kernel modules

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 administration
• Why GNU su does not support the wheel group
• Enforcing stricter password policies
• Implementing additional access controls
• Configuring sudo
• Using SELinux and AppArmor
• Restricting access to specific server services
• Securing authentication processes
• Transmitting passwords securely over the internet
• Using Secure Shell (SSH)
• Additional internet security measures
• Securing the root password

Network setup

Basic network infrastructure

• Understanding domain names
• Hostname resolution mechanisms
• Naming network interfaces
• Defining LAN network address ranges
• Network device driver support

Modern network configuration for desktops

• Using GUI-based network configuration tools

Low-level network configuration

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

Network optimization

• Identifying the optimal MTU
• Setting the MTU value
• Optimizing TCP for WAN connections

Netfilter infrastructure

Network applications

The mail system

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

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

• Overview of exim4
• Basic MUA usage with Mutt

Mail Delivery Agent (MDA) with filtering

• Configuring maildrop
• Configuring procmail
• Redelivering mbox content

POP3/IMAP4 server

Remote access server and utilities (SSH)

• SSH fundamentals
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote password prompts
• Handling non-standard 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 architecture
• Starting the X Window System
• Launching X sessions with gdm
• Customizing X sessions (traditional method)
• Customizing X sessions (modern method)
• Connecting remote X clients via SSH
• Secure X terminals over the internet
• Running X applications
• X-based office applications
• X-based utility applications

System tips

The screen program

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

Data recording and presentation

• Managing the log daemon
• Using log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Adding colors to shell echo output
• Colorizing command outputs
• Recording editor activities for complex repetitions
• Capturing graphic images of X applications
• Tracking changes in configuration files

Data storage tips

• Configuring disk partitions
• Accessing partitions using UUIDs
• Configuring filesystems
• Creating filesystems and checking integrity
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock settings
• Optimizing hard disk performance
• Predicting hard disk failure using SMART
• Expanding usable storage with LVM
• Expanding storage by mounting additional partitions
• Expanding storage using symbolic links
• Expanding storage using aufs

Data encryption tips

• Encrypting removable disks with dm-crypt/LUKS
• Encrypting swap partitions with dm-crypt
• Automatically encrypting files with eCryptfs
• Auto-mounting eCryptfs volumes

Monitoring, controlling, and starting program activities

• Timing process execution
• Managing scheduling priority
• Using the ps command
• Using the top command
• Listing files opened by a process
• Tracing program behavior
• Identifying processes using specific files or sockets
• Repeating commands at constant intervals
• Looping commands over file lists
• Starting programs from the GUI
• Customizing startup programs
• Terminating processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System maintenance tips

• Identifying users on the system
• Broadcasting system warnings
• Identifying hardware
• Configuring hardware
• Synchronizing system and hardware time
• Configuring terminal settings
• Managing the sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• Performing system security and integrity checks

The kernel

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

Virtualized systems

• Available 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 tools
• Copy and synchronization tools
• Common archive idioms
• Common copy idioms
• Idioms for file selection
• Backup and recovery strategies
• Backup utility suites
• Example scripts for system backup
• Scripts for data copying
• Handling removable storage devices
• Sharing data over the network
• Using archive media

Binary data handling

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

Data security infrastructure

• Key management with GnuPG (signing and encryption)
• Using MD5 checksums