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
• Shell prompt behavior in the X environment
• Root account and root shell access (su, sudo, executing commands as root under X)
• Graphical system administration tools
• Virtual consoles
• Exiting the command prompt
• System shutdown procedures
• Restoring a stable console session
• Recommended additional packages for beginners
• Creating additional user accounts
• Configuring sudo

The filesystem

• File permissions
• Controlling permissions for new files: umask
• Group-based permissions
• Timestamps
• Symbolic and hard links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• procfs and sysfs

Midnight Commander (MC)

• Customizing MC
• Launching MC
• File management within MC
• Command-line techniques in MC
• The internal editor in MC
• The internal viewer in MC
• MC auto-start capabilities
• FTP virtual filesystem support in MC

Essential Unix-like work environment

• The login shell
• Customizing bash
• Special key sequences
• Using the pager
• Setting a default text editor
• Exiting vim
• Logging shell activities
• Fundamental 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
• Common command sequences and shell redirection
• Command aliases

Unix-style text processing

• Unix text utilities
• Regular expressions
• Replacement patterns
• Global substitution using regular expressions
• Extracting data from tabular text files
• Script snippets for command piping

Debian package management

Prerequisites for Debian package management

• Package configuration
• Basic safety measures
• Managing continuous upgrades
• Debian archive fundamentals
• Package dependencies
• The workflow of package management
• Initial steps for resolving package issues

Fundamental package management operations

• Comparison of apt-get/apt-cache vs. aptitude
• Basic package operations via the command line
• Interactive use of aptitude
• aptitude key bindings
• Package views in aptitude
• Search options with aptitude
• aptitude regex formulas
• Dependency resolution in aptitude
• Package activity logs

aptitude operation examples

• Listing packages with regex matching on names
• Browsing using regex matching
• Thoroughly purging removed packages
• Organizing auto/manual install status
• System-wide upgrades

Advanced package management operations

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

Debian package management internals

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

Recovering from a broken system

• Issues with old user configurations
• Conflicts between packages with overlapping files
• Correcting broken package scripts
• Rescue operations using dpkg
• Restoring package selection data

Package management tips

• Choosing Debian packages
• Using packages from mixed archive sources
• Adjusting candidate versions
• Handling updates and Backports
• Automatic package download and upgrade
• Limiting APT download bandwidth
• Emergency downgrades
• Identifying package uploaders
• The equivs package
• Porting packages to stable systems
• Configuring an APT proxy server
• Setting up a small public package archive
• Recording and copying system configurations
• Converting or installing non-native binary packages
• Extracting packages without dpkg
• Further reading on package management

System initialization

• Overview of the bootstrapping process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Runlevel management examples
• Default parameters for init scripts
• Hostname configuration
• Filesystem setup
• 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 data
• Creating strong passwords
• Generating encrypted passwords
• PAM and NSS
• Configuration files for PAM and NSS
• Modern centralized system management
• Why GNU su does not support the wheel group
• Implementing stricter password policies
• Other access control methods
• Using sudo
• SELinux and AppArmor
• Restricting access to specific server services
• Securing authentication
• Secure password transmission over the internet
• Secure Shell (SSH)
• Additional internet security measures
• Securing the root password

Network setup

Basic network infrastructure

• Domain names
• Hostname resolution
• Network interface naming
• LAN network 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 the 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)

• Introduction to 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
• Handling non-standard 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
• Server/client relationships
• The X server
• Starting the X Window System
• Starting an X session with gdm
• Customizing the X session (traditional method)
• Customizing the X session (modern method)
• Connecting a remote X client via SSH
• Secure 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 analysis tools
• Cleanly recording shell activities
• Custom text data display
• Custom time and date display
• Colorized shell echo
• Colorized commands
• Recording editor actions for complex repetitions
• Capturing X application graphics
• Tracking configuration file changes

Data storage tips

• Disk partition setup
• Accessing partitions via UUID
• Filesystem configuration
• Creating and checking filesystem integrity
• Filesystem optimization via mount options
• Filesystem optimization via superblock
• Hard disk optimization
• Predicting hard disk failures using SMART
• Expanding usable storage with LVM
• Expanding storage by mounting additional partitions
• Expanding storage using symlinks
• 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
• Automatically mounting eCryptfs volumes

Monitoring, controlling, and starting program activities

• Timing processes
• Scheduling priorities
• The ps command
• The top command
• Listing files opened by a process
• Tracing program activities
• Identifying processes using files or sockets
• Repeating commands at constant intervals
• Repeating commands by looping over files
• Launching programs from the GUI
• Customizing programs to start
• Terminating processes
• Scheduling one-time tasks
• Scheduling recurring tasks
• The Alt-SysRq key

System maintenance tips

• Identifying active users
• Sending warnings to all users
• Hardware identification
• Hardware configuration
• System and hardware time synchronization
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Memory usage monitoring
• System security and integrity checks

The kernel

• Kernel parameters
• Kernel headers
• Compiling the kernel and related modules
• Compiling the kernel source: Debian standard approach
• Compiling module sources: Debian standard approach
• Non-free hardware drivers

Virtualized systems

• Virtualization tools
• Virtualization workflows
• 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
• Archiving idioms
• Copying idioms
• File selection idioms
• Backup and recovery
• Backup utility suites
• Sample script for system backup
• Sample script for data backup
• Removable storage devices
• Sharing data over the network
• Archive media

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 ones
• Clearing file contents
• Creating dummy files
• Wiping an entire hard disk
• Wiping unused areas of a hard disk
• Restoring deleted but still open files
• Finding all hard links
• Invisible disk space consumption

Data security infrastructure

• GnuPG key management (signing and encryption)
• MD5 checksums