Debian Administration Training Course

Debian Distribution

What is Debian?

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

Console fundamentals

• Understanding the shell prompt
• Using the shell prompt within the X environment
• The root account and root shell prompt (utilizing su, sudo, and executing programs as root in X)
• Graphical user interface (GUI) system administration tools
• Virtual consoles
• Exiting the command prompt
• Shutting down the system properly
• Restoring a functional console state
• Recommended packages for beginners
• Setting up an additional user account
• Configuring sudo

The filesystem

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

Midnight Commander (MC)

• Customizing MC
• Launching MC
• Navigating files in MC
• Command-line techniques within MC
• Using MC's internal editor
• Using MC's internal viewer
• Auto-start features of MC
• MC's FTP virtual filesystem

Basic Unix-like work environment

• Configuring the login shell
• Customizing bash
• Essential keyboard shortcuts
• Using the pager
• 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
• Typical command sequences and shell redirection
• Command aliases

Unix-like text processing

• Unix text processing 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 precautions
• Managing continuous upgrades
• Basics of the Debian archive
• Package dependencies
• Package management workflow
• Initial responses to package management issues

Basic package management operations

• Comparing apt-get/apt-cache with aptitude
• Basic package management via command line
• Interactive use of aptitude
• aptitude key bindings
• Package views in aptitude
• Search method options in aptitude
• The aptitude regex formula
• Dependency resolution in aptitude
• Package activity logs

Examples of aptitude operations

• Listing packages with regex matching on package names
• Browsing using regex matching
• Purging removed packages permanently
• Adjusting auto/manual installation status
• Performing a system-wide upgrade

Advanced package management operations

• Advanced package management via command line
• Verifying installed package files
• Precautions against 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
• APT package state
• aptitude package state
• Local copies of fetched packages
• Debian package file naming conventions
• The dpkg command
• The update-alternative command
• The dpkg-statoverride command
• The dpkg-divert command

Recovery from a broken system

• Resolving incompatibility with old user configurations
• Handling overlapping files in different packages
• Fixing broken package scripts
• Using dpkg for rescue operations
• Recovering package selection data

Tips for package management

• Selecting Debian packages
• Managing packages from mixed archive sources
• Adjusting candidate versions
• Updates and Backports
• Automatic package download and upgrade
• Limiting APT download bandwidth
• Emergency downgrading
• Identifying package uploaders
• The equivs package
• Porting packages to stable systems
• APT proxy server configuration
• Small public package archives
• Recording and copying system configurations
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Further readings on package management

The system initialization

• Overview of the boot strap process
• BIOS, boot loader, and mini-Debian system
• Understanding runlevels
• Configuring runlevels
• Runlevel management examples
• Default parameters for init scripts
• The hostname
• The filesystem
• 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 information
• Creating strong passwords
• Generating encrypted passwords
• PAM and NSS
• Configuration files accessed by PAM and NSS
• Modern centralized system management
• "Why GNU su does not support the wheel group"
• Enforcing stricter password rules
• Other access controls
• sudo
• SELinux and Apparmor
• Restricting access to specific server services
• Authentication security
• Secure password transmission over the Internet
• Secure Shell
• Additional security measures for the Internet
• Securing the root password

Network setup

The basic network infrastructure

• The domain name
• 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

• Iproute2 commands
• Safe low-level network operations

Network optimization

• Finding optimal MTU
• Setting MTU
• WAN TCP optimization

Netfilter infrastructure

Network applications

The mail system

• Modern mail service basics
• Mail configuration strategy for workstations

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

• Overview of exim4
• Basic MUA - Mutt

Mail delivery agent (MDA) with filter

• maildrop configuration
• procmail configuration
• Redelivering mbox contents

POP3/IMAP4 server

The remote access server and utility (SSH)

• SSH basics
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Handling 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
• 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 X terminals 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

• The log daemon
• Log analyzers
• Cleanly recording shell activities
• Customizing text data display
• Customizing date and time display
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repeats
• Recording X application graphic images
• 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
• Hard disk optimization
• Using SMART to predict hard disk failure
• Expanding usable storage via LVM
• Expanding usable storage by mounting additional partitions
• Expanding usable storage using symlinks
• Expanding usable storage using aufs

Data encryption tips

• Removable disk encryption with dm-crypt/LUKS
• Encrypted swap partition with dm-crypt
• Automatically encrypting files with eCryptfs
• Automounting eCryptfs

Monitoring, controlling, and starting program activities

• Timing a process
• Setting scheduling priority
• The ps command
• 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 in a loop over 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

• Monitoring system users
• Warning all users
• Hardware identification
• Hardware configuration
• System and hardware time
• Terminal configuration
• Sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Memory usage
• System security and integrity checks

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 system

• Virtualization tools
• Virtualization workflow
• Mounting virtual disk image files
• Chroot system
• 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

The 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
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Undeleting deleted but still open files
• Searching all hardlinks
• Identifying invisible disk space consumption

Data security infrastructure

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