Debian Administration Training Course

Debian Distribution

What is Debian?

• Selecting a Debian version
• Debian support and assistance resources
• The Debian community

Console fundamentals

• The shell prompt interface
• Using the shell prompt within the X environment
• Root account management and root shell prompts (su, sudo, executing programs as root in X)
• Graphical user interface (GUI) administration tools
• Virtual consoles
• Exiting the command prompt
• Shutting down the system
• Restoring a functional console
• Recommended packages for beginners
• Creating additional user accounts
• Configuring sudo

The filesystem

• Filesystem permission structures
• Managing permissions for new files using umask
• Group-based permissions
• Timestamps
• File links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• The procfs and sysfs virtual filesystems

Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Using the MC file manager
• Command-line techniques in MC
• The internal MC editor
• The internal MC viewer
• MC auto-start capabilities
• The MC FTP virtual filesystem

The basic Unix-like work environment

• The login shell
• Customizing bash
• Special keyboard shortcuts
• Using the pager utility
• Setting a default text editor
• Exiting vim
• Logging shell activities
• Essential Unix commands

Simple shell commands

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

Unix-like text processing

• Standard Unix text tools
• Regular expressions
• Replacement expressions
• Global substitution using regular expressions
• Extracting data from text file tables
• Script snippets for piping commands

Debian package management

Prerequisites for Debian package management

• Package configuration
• Basic safety precautions
• Managing systems with continuous upgrades
• Basics of Debian archives
• Package dependencies
• The workflow of package management
• Initial steps for resolving package management issues

Basic package management operations

• Comparing apt-get/apt-cache with aptitude
• Core package management via the command line
• Interactive use of aptitude
• aptitude key bindings
• Package views in aptitude
• Search options in aptitude
• The aptitude regular expression syntax
• Dependency resolution in aptitude
• Package activity logs

aptitude operation examples

• Listing packages by regular expression matching
• Browsing with regular expression matching
• Permanently removing purged packages
• Cleaning up auto/manual installation states
• Performing system-wide upgrades

Advanced package management operations

• Advanced command-line package management
• Verifying installed package files
• Protecting against package issues
• Searching package metadata

Debian package management internals

• Archive metadata
• The top-level "Release" file and authenticity
• Archive-level "Release" files
• Retrieving package metadata
• Package state management in APT
• Package state management in aptitude
• Local storage of downloaded packages
• Debian package naming conventions
• The dpkg command
• The update-alternative command
• The dpkg-statoverride command
• The dpkg-divert command

Recovering from a broken system

• Resolving conflicts with legacy user configurations
• Handling packages with overlapping files
• Repairing broken package scripts
• Using dpkg for system rescue
• Restoring package selection data

Package management tips

• Criteria for selecting Debian packages
• Using packages from mixed archive sources
• Adjusting candidate versions
• Updates and Backports repositories
• Automating package downloads and upgrades
• Limiting APT download bandwidth
• Emergency downgrades
• Identifying package uploaders
• The equivs package
• Porting packages to stable systems
• Configuring proxy servers for APT
• Setting up small public package archives
• Recording and duplicating system configurations
• Converting or installing non-Debian binary packages
• Extracting packages without using dpkg
• Further reading on package management

System initialization

• Overview of the bootstrapping process
• BIOS, boot loaders, and the mini-Debian system
• Understanding runlevels
• Configuring runlevels
• Example of runlevel management
• Default parameters for init scripts
• Hostname configuration
• Filesystem mounting
• Network interface initialization
• Network service initialization
• System messages
• Kernel messages
• The udev system
• Kernel module initialization

Authentication and Security

• Standard Unix authentication
• Managing account and password details
• Creating strong passwords
• Generating encrypted passwords
• PAM and NSS frameworks
• Configuration files used by PAM and NSS
• Modern centralized system administration
• Reasons GNU su does not support the wheel group
• Implementing stricter password policies
• Additional access control methods
• Using sudo
• SELinux and AppArmor
• Restricting access to specific server services
• Authentication security practices
• Securing passwords over the Internet
• Secure Shell (SSH)
• Extra security measures for internet connections
• Securing the root password

Network setup

Basic network infrastructure

• Domain names
• Hostname resolution
• Network interface naming
• Local Area Network (LAN) address ranges
• Network device support

Modern desktop network configuration

• GUI-based network configuration tools

Low-level network configuration

• Iproute2 commands
• Safe low-level network operations

Network optimization

• Determining the optimal MTU
• Configuring MTU
• WAN TCP optimization

Netfilter infrastructure

Network applications

The mail system

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

Mail transport agent (MTA) and Mail user agent (MUA)

• Overview of exim4
• Basic MUA usage with 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 non-standard SSH clients
• Configuring 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
• The server/client model
• The X server
• 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
• Securing X terminals over the Internet
• X applications
• X office suite 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 sessions
• Customizing text data display
• Customizing date and time display
• Colorized shell output
• Colorized commands
• Recording editor actions for complex repetitions
• Capturing graphics from X applications
• Tracking changes in configuration files

Data storage tips

• Disk partition setup
• Accessing partitions via UUID
• Filesystem configuration
• Creating filesystems and running integrity checks
• Optimizing filesystems with mount options
• Optimizing filesystems via superblocks
• Optimizing hard disk performance
• Predicting hard disk failures with SMART
• Expanding storage space with LVM
• Expanding storage space by mounting additional partitions
• 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
• Automatic file encryption with eCryptfs
• Automatic mounting of eCryptfs volumes

Monitoring, controlling, and starting program activities

• Timing processes
• Scheduling priority
• The ps command
• The top command
• Listing files opened by a process
• Tracing program activity
• Identifying processes using specific files or sockets
• Repeating commands at fixed intervals
• Looping commands over file sets
• Launching programs from the GUI
• Customizing startup programs
• Terminating processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• The Alt-SysRq key

System maintenance tips

• Checking logged-in users
• Broadcasting system warnings
• Hardware identification
• Hardware configuration
• Synchronizing system and hardware time
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• System security and integrity verification

The kernel

• Kernel parameters
• Kernel headers
• Compiling the kernel and associated modules
• Compiling kernel sources: Debian standard method
• Compiling module sources: Debian standard method
• Non-free hardware drivers

Virtualized systems

• Virtualization tools
• Virtualization workflows
• Mounting virtual disk images
• Chroot environments
• Managing multiple desktop systems

Data management

Sharing, copying, and archiving

• Archiving and compression tools
• Copying and synchronization utilities
• Common archive idioms
• Common copy idioms
• File selection idioms
• Backup and recovery procedures
• Backup utility suites
• Example system backup script
• Data backup copy script
• Managing removable storage devices
• Sharing data over the network
• Archive media management

Binary data

• Viewing and editing binary data
• Manipulating files without mounting disks
• Data redundancy
• Data file recovery and forensic analysis
• Splitting large files into smaller segments
• Clearing file contents
• Creating dummy files
• Wiping an entire hard disk
• Erasing unused hard disk space
• Restoring deleted but open files
• Finding all hard links
• Invisible disk space usage

Data security infrastructure

• Key management for GnuPG (signing and encryption)
• MD5 checksums