Debian Administration Training Course

Debian Distribution

What is Debian?

• Choosing the appropriate Debian version
• Understanding Debian support and help resources
• Engaging with the Debian community

Console fundamentals

• Understanding the shell prompt
• Managing the shell prompt in a graphical environment (X)
• Utilizing the root account and root shell prompt (su, sudo, and running programs as root under X)
• Overview of GUI system administration tools
• Using virtual consoles
• Exiting the command prompt correctly
• Properly shutting down the system
• Recovering a malfunctioning console
• Recommended additional packages for newcomers
• Setting up an extra user account
• Configuring sudo

The filesystem

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

Midnight Commander (MC)

• Customizing MC settings
• Launching MC
• Navigating the file manager within MC
• Utilizing command-line tricks in MC
• Using the internal editor in MC
• Using the internal viewer in MC
• Enabling auto-start features of MC
• Accessing the FTP virtual filesystem in MC

The basic Unix-like work environment

• Understanding the login shell
• Customizing bash
• Mastering special key strokes
• Using the pager
• Setting a default text editor
• Exiting vim
• Recording 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
• Shell globbing
• Interpreting command return values
• Utilizing typical command sequences and shell redirection
• Creating command aliases

Unix-like text processing

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

Debian package management

Debian package management prerequisites

• Configuring packages
• Implementing basic precautions
• Managing life with constant upgrades
• Understanding Debian archive basics
• Understanding package dependencies
• Understanding the event flow of package management
• Providing initial responses to package management issues

Basic package management operations

• Comparing apt-get/apt-cache vs. aptitude
• Executing basic package management operations via the command line
• Using aptitude interactively
• Utilizing key bindings in aptitude
• Navigating package views under aptitude
• Using search method options with aptitude
• Utilizing the aptitude regex formula
• 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
• Completely purging removed packages
• Organizing auto/manual install statuses
• Performing a system-wide upgrade

Advanced package management operations

• Executing advanced package management operations via the command line
• Verifying installed package files
• Safeguarding against package problems
• Searching package metadata

Debian package management internals

• Archive metadata
• The top-level "Release" file and its authenticity
• Archive-level "Release" files
• Fetching metadata for packages
• The package state for APT
• The 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 incompatibility with old user configurations
• Managing different packages with overlapping files
• Fixing broken package scripts
• Rescuing the system with the dpkg command
• Recovering package selection data

Tips for package management

• How to select Debian packages
• Handling packages from mixed archive sources
• Tweaking candidate versions
• Understanding updates and backports
• Automating package download and upgrade processes
• Limiting download bandwidth for APT
• Performing emergency downgrades
• Identifying who uploaded a package
• Using the equivs package
• Porting a package to a stable system
• Configuring a proxy server for APT
• Managing a small public package archive
• Recording and copying system configuration
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Additional readings for package management

The system initialization

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

Authentication and Security

• Standard Unix authentication
• Managing account and password information
• Creating strong passwords
• Creating 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"
• Implementing stricter password rules
• Exploring other access controls
• Using sudo
• Implementing SELinux and Apparmor
• Restricting access to specific server services
• Ensuring authentication security
• Securing passwords over the Internet
• Implementing Secure Shell
• Implementing extra security measures for the Internet
• Securing the root password

Network setup

The basic network infrastructure

• Configuring the domain name
• Configuring hostname resolution
• Configuring network interface names
• Configuring the network address range for the LAN
• Configuring network device support

Modern network configuration for desktops

• Using 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

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 server

The remote access server and utility (SSH)

• SSH basics
• Setting up port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Managing incompatible SSH clients
• Setting up ssh-agent
• Shutting down the remote system via SSH
• Troubleshooting SSH

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 (new method)
• Connecting a remote X client via SSH
• Securing the X terminal via 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

• Configuring 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 graphic image of an X application
• Recording changes in configuration files

Data storage tips

• Disk partition configuration
• Accessing partitions using UUID
• Filesystem configuration
• Creating filesystems and performing integrity checks
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock
• Optimizing hard disks
• 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
• Automounting eCryptfs

Monitoring, controlling, and starting program activities

• Timing a process
• Managing 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 a command at a constant interval
• Repeating a command while looping over files
• Starting a program from the GUI
• Customizing programs to be started
• Killing a process
• Scheduling one-time tasks
• Scheduling recurring tasks
• Using the Alt-SysRq key

System maintenance tips

• Identifying who is on the system
• Warning all users
• Hardware identification
• Hardware configuration
• Managing system and hardware time
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Monitoring memory usage
• Performing system security and integrity checks

The kernel

• Kernel parameters
• Kernel headers
• Compiling the kernel and related modules
• Compiling the kernel source: Debian standard method
• Compiling the 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
• Idioms for archiving
• Idioms for copying
• Idioms for file selection
• Backup and recovery
• Backup utility suites
• Example script for system backup
• Copy script for data backup
• Removable storage devices
• Sharing data via the 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 files that are deleted but still open
• Searching for all hard links
• Identifying invisible disk space consumption

Data security infrastructure

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