Debian Administration Training Course

Debian Distribution

What is Debian?

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

Console essentials

• Understanding the shell prompt
• Operating the shell prompt within the X environment
• Utilizing the root account and root shell prompt (su, sudo, running programs as root under X)
• GUI-based system administration tools
• Using virtual consoles
• Exiting the command prompt correctly
• Properly shutting down the system
• Restoring a functional console session
• Recommended additional packages for beginners
• Creating an extra user account
• Configuring sudo permissions

The filesystem

• Understanding filesystem permissions
• Controlling permissions for new files: using umask
• Managing permissions for user groups
• Working with timestamps
• Creating and managing links
• Using named pipes (FIFOs)
• Understanding sockets
• Working with device files
• Distinguishing special device files
• Utilizing procfs and sysfs

Midnight Commander (MC)

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

The basic Unix-like work environment

• Understanding the login shell
• Customizing bash
• Using special keystrokes
• Utilizing the pager
• Setting a default text editor
• Exiting vim properly
• Logging shell activities
• Executing basic Unix commands

Simple shell commands

• Command execution and environment variables
• Understanding the "$LANG" variable
• Understanding the "$PATH" variable
• Understanding the "$HOME" variable
• Using command line options
• Utilizing shell globbing
• Checking command return values
• Executing typical command sequences and shell redirection
• Creating command aliases

Unix-like text processing

• Using Unix text tools
• Understanding regular expressions
• Using replacement expressions
• Performing global substitutions with regular expressions
• Extracting data from text file tables
• Writing script snippets for piping commands

Debian package management

Debian package management prerequisites

• Configuring packages
• Essential precautions
• Managing long-term upgrades
• Understanding Debian archive basics
• Managing package dependencies
• Understanding the package management event flow
• Initial troubleshooting for package management issues

Basic package management operations

• Comparing apt-get/apt-cache vs. aptitude
• Performing basic package management via the command line
• Using aptitude interactively
• Understanding aptitude key bindings
• Navigating package views in aptitude
• Using search method options with aptitude
• Constructing aptitude regex formulas
• Resolving dependencies with aptitude
• Reviewing package activity logs

Examples of aptitude operations

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

Advanced package management operations

• Performing advanced package management operations via command line
• Verifying installed package files
• Implementing safeguards against package issues
• Searching package metadata

Debian package management internals

• Understanding archive metadata
• Examining the top-level "Release" file and authenticity
• Understanding archive-level "Release" files
• Fetching package metadata
• Understanding package state for APT
• Understanding package state for aptitude
• Managing 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

Recovery from a broken system

• Handling incompatibilities with old user configurations
• Resolving conflicts between packages with overlapping files
• Fixing broken package scripts
• Rescuing the system using the dpkg command
• Recovering package selection data

Tips for package management

• Selecting appropriate Debian packages
• Managing packages from mixed archive sources
• Adjusting candidate versions
• Handling updates and backports
• Automating package downloads and upgrades
• Limiting download bandwidth for APT
• 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 resources for package management

The system initialization

• Overview of the bootstrapping process
• BIOS, boot loader, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Runlevel management examples
• Default parameters for each init script
• Managing the hostname
• Mounting the filesystem
• Initializing network interfaces
• Initializing network services
• Managing system messages
• Interpreting kernel messages
• Understanding the udev system
• Initializing kernel modules

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
• Enforcing stricter password rules
• Implementing other access controls
• Configuring sudo
• Using SELinux and AppArmor
• Restricting access to specific server services
• Ensuring authentication security
• Securing passwords over the Internet
• Using Secure Shell (SSH)
• Implementing additional security measures for Internet connectivity
• Securing the root password

Network setup

The basic network infrastructure

• Managing domain names
• Performing hostname resolution
• Understanding network interface naming
• Defining network address ranges for LAN
• Ensuring network device support

Modern network configuration for desktops

• Utilizing GUI network configuration tools

Low-level network configuration

• Using iproute2 commands
• Performing safe low-level network operations

Network optimization

• Finding the optimal MTU
• Setting the MTU
• Optimizing WAN TCP performance

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
• Using the basic MUA: Mutt

Mail delivery agent (MDA) with filters

• Configuring maildrop
• Configuring procmail
• Redelivering mbox contents

POP3/IMAP4 servers

Remote access server and utilities (SSH)

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

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
• Configuring 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
• Utilizing X applications
• Using X office applications
• Using 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
• Using log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Using colorized shell echo
• Using colorized commands
• Recording editor activities for complex repetitions
• Recording the graphical image of an X application
• Recording changes in configuration files

Data storage tips

• Configuring disk partitions
• Accessing partitions using UUID
• Configuring filesystems
• Creating filesystems and performing integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock
• Optimizing hard disk performance
• 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 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 with eCryptfs
• Automatically mounting eCryptfs

Monitoring, controlling, and starting program activities

• Timing processes
• Adjusting 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 commands at constant intervals
• Looping commands over files
• 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 logged-in users
• Notifying all users
• Identifying hardware
• Configuring hardware
• Managing system and hardware time
• Configuring the terminal
• 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
• Understanding 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

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

Data management

Sharing, copying, and archiving

• Using archive and compression tools
• Using copy and synchronization tools
• Archive idioms and best practices
• Copy idioms and best practices
• File selection idioms
• Backup and recovery strategies
• Backup utility suites
• Example scripts for system backup
• Scripts for data backup copies
• Managing removable storage devices
• Sharing data via network
• Using archive media

Binary data

• Viewing and editing binary data
• Manipulating files without mounting disk
• Ensuring 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 hard links
• Accounting for invisible disk space consumption

Data security infrastructure

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