Debian Administration Training Course

Debian Distribution

What is Debian?

• Selecting the appropriate Debian version
• Debian support channels and assistance
• The Debian community

Console fundamentals

• Understanding the shell prompt
• Using the shell prompt within the X environment
• Managing the root account and root shell prompt (using su, sudo, and executing programs as root under X)
• Graphical user interface (GUI) system administration tools
• Navigating virtual consoles
• Exiting the command prompt
• Shutting down the system properly
• Restoring a functional console state
• Recommended additional packages for beginners
• Creating an extra user account
• Configuring sudo

The filesystem

• Filesystem permissions
• Controlling permissions for newly created files: umask
• Managing permissions for user groups (group)
• Understanding file timestamps
• Working with links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• Using procfs and sysfs

Midnight Commander (MC)

• Customizing MC
• Launching MC
• Using MC as a file manager
• Command-line tricks within MC
• Using the internal editor in MC
• Using the internal viewer in MC
• MC auto-start features
• MC's FTP virtual filesystem

The basic Unix-like work environment

• Understanding the login shell
• Customizing bash
• Special key strokes
• Using the pager
• Setting a default text editor
• Exiting vim
• Recording shell activities
• Essential 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
• Typical command sequences and shell redirection
• Creating command aliases

Unix-like text processing

• Unix text utilities
• 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 precautions
• Managing system upgrades
• Debian archive fundamentals
• Understanding package dependencies
• The workflow of package management
• Initial responses to package management issues

Basic package management operations

• Comparing apt-get/apt-cache with aptitude
• Performing basic package management operations via the command line
• Interactive use of aptitude
• Key bindings in aptitude
• Navigating package views in aptitude
• Search options in aptitude
• Using aptitude regex patterns
• Dependency resolution in aptitude
• Reviewing package activity logs

Examples of aptitude operations

• Listing packages with regex matching on package names
• Browsing using regex matching
• Completely purging removed packages
• Managing automatic versus manual installation status
• Performing a system-wide upgrade

Advanced package management operations

• Performing advanced package management operations via the command line
• Verifying installed package files
• Preventing and resolving package problems
• Searching package metadata

Debian package management internals

• Archive metadata
• The top-level "Release" file and authenticity
• Archive-level "Release" files
• Fetching package metadata
• Package state for APT
• Package state for aptitude
• Local copies of fetched packages
• 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
• Managing different packages with overlapping files
• Fixing broken package scripts
• Rescuing systems using the dpkg command
• Recovering package selection data

Tips for package management

• Selecting Debian packages effectively
• Managing packages from mixed archive sources
• Adjusting candidate versions
• Understanding Updates and Backports
• Automating package downloads and upgrades
• Limiting APT download bandwidth
• Emergency downgrading
• Identifying package uploaders
• Using the equivs package
• Porting packages to a stable system
• Configuring a proxy server for APT
• Creating a small public package archive
• Recording and copying system configurations
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Further reading for package management

System initialization

• Overview of the boot process
• BIOS, boot loaders, and mini-Debian systems
• Understanding runlevels
• Configuring runlevels
• Runlevel management examples
• Default parameters for init scripts
• Setting the hostname
• Filesystem initialization
• Initializing network interfaces
• Initializing network services
• System messages
• Kernel messages
• The udev system
• Kernel module initialization

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
• "Why GNU su does not support the wheel group"
• Implementing stricter password rules
• Other access control methods
• Using sudo
• SELinux and AppArmor
• Restricting access to specific server services
• Ensuring authentication security
• Securing passwords over the Internet
• Using Secure Shell
• Additional security measures for Internet connectivity
• Securing the root password

Network setup

Basic network infrastructure

• Understanding domain names
• Hostname resolution
• Network interface naming
• LAN network address ranges
• Network device support

Modern network configuration for desktop

• GUI network configuration tools

Low-level network configuration

• Using Iproute2 commands
• Safely performing low-level network operations

Network optimization

• Finding the optimal MTU
• Setting the MTU
• WAN TCP optimization

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
• Basic MUA: Mutt

Mail delivery agent (MDA) with filters

• Configuring maildrop
• Configuring procmail
• Redelivering mbox contents

POP3/IMAP4 servers

Remote access servers and utilities (SSH)

• SSH basics
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Managing incompatible 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
• Understanding the server/client relationship
• The X server
• Starting the X Window System
• Starting an X session with gdm
• Customizing the X session (classic method)
• Customizing the X session (modern method)
• Connecting a remote X client via SSH
• Using a secure X terminal 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 analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing time and date display
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repetitions
• Recording the graphic image of an X application
• Recording changes in configuration files

Data storage tips

• Disk partition configuration
• Accessing partitions using UUID
• Filesystem configuration
• Filesystem creation and integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblocks
• Optimizing hard disks
• Using SMART to predict hard disk failures
• Expanding usable storage space via LVM
• Expanding usable storage space by mounting additional partitions
• Expanding usable storage space using symlinks
• 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
• Setting scheduling priorities
• Using the ps command
• Using the top command
• Listing files opened by a process
• Tracing program activities
• Identifying processes using files or sockets
• Repeating a command at constant intervals
• Repeating a command over multiple files
• Starting a program from the GUI
• Customizing startup programs
• Killing a process
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System maintenance tips

• Checking who is on the system
• Notifying all users
• Hardware identification
• Hardware configuration
• System and hardware time settings
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• Checking system security and integrity

The kernel

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

Virtualized systems

• Virtualization tools
• Virtualization workflow
• 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
• Archive idioms
• Copy idioms
• File selection idioms
• Backup and recovery
• Backup utility suites
• Example script for system backup
• Script for data backup copying
• Removable storage devices
• Sharing data via network
• Archive media

Binary data

• Viewing and editing binary data
• Manipulating files without mounting the disk
• 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
• Understanding invisible disk space consumption

Data security infrastructure

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