Debian Administration Training Course

Debian Distribution

Understanding Debian

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

Console fundamentals

• The shell prompt
• The shell prompt within the X environment
• Root account and root shell prompt (su, sudo, executing programs as root under X)
• Graphical system administration tools
• Virtual consoles
• Exiting the command prompt
• Shutting down the system
• Restoring a functional console
• Additional package recommendations for beginners
• Creating an additional user account
• Configuring sudo

The filesystem

• Filesystem permissions
• Controlling permissions for new files: umask
• Permissions for user groups
• Timestamps
• Symlinks and hard links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• procfs and sysfs

Midnight Commander (MC)

• Customizing MC
• Launching MC
• The file manager within MC
• Command-line techniques in MC
• The built-in editor in MC
• The built-in viewer in MC
• MC auto-start capabilities
• MC's FTP virtual filesystem

The fundamental Unix-like work environment

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

The simple shell command

• 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

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

Fundamental package management operations

• apt-get/apt-cache vs. aptitude
• Basic package management via the command line
• Interactive use of aptitude
• aptitude key bindings
• Package views in aptitude
• Search options in aptitude
• The aptitude regex formula
• aptitude dependency resolution
• Package activity logs

Examples of aptitude operations

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

Advanced package management operations

• Advanced package management via the command line
• Verifying installed package files
• Mitigating package issues
• Searching package metadata

Internals of Debian package management

• Archive metadata
• Top-level "Release" file and authenticity
• Archive-level "Release" files
• Fetching 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-alternatives command
• The dpkg-statoverride command
• The dpkg-divert command

Recovering from a broken system

• Incompatibility with legacy user configurations
• Conflicts from overlapping package files
• Repairing broken package scripts
• Rescue using the dpkg command
• Restoring package selection data

Package management tips

• Selecting appropriate Debian packages
• Packages from mixed archive sources
• Adjusting candidate versions
• Updates and Backports
• Automated package download and upgrade
• Limiting APT download bandwidth
• Emergency downgrading
• 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 duplicating system configurations
• Converting or installing foreign binary packages
• Extracting packages without dpkg
• Further reading on package management

System initialization

• Overview of the bootstrap process
• BIOS, boot loader, and mini-Debian systems
• The concept of runlevels
• Configuring runlevels
• Examples of runlevel management
• Default parameters for init scripts
• Hostname configuration
• Filesystem configuration
• 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
• Constructing strong passwords
• Creating encrypted passwords
• PAM and NSS
• Configuration files used by PAM and NSS
• Modern centralized system administration
• Why GNU su does not support the wheel group
• Implementing stricter password policies
• Other access control mechanisms
• sudo usage
• SELinux and AppArmor
• Restricting access to specific server services
• Authentication security
• Securing passwords over the Internet
• Secure Shell (SSH)
• Additional internet security measures
• Securing the root password

Network setup

Fundamental network infrastructure

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

Modern desktop network configuration

• Graphical network configuration tools

Low-level network configuration

• Iproute2 commands
• Safe low-level network operations

Network optimization

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

Netfilter infrastructure

Network applications

The mail system

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

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

• Overview of exim4
• Basic MUA - Mutt

Mail delivery agents (MDA) with filters

• maildrop configuration
• procmail configuration
• Redelivering mbox contents

POP3/IMAP4 server

Remote access servers and utilities (SSH)

• SSH fundamentals
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Handling external 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
• Launching the X Window System
• Starting X sessions with gdm
• Customizing X sessions (traditional method)
• Customizing X sessions (modern method)
• Connecting remote X clients 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 analyzers
• Cleanly recording shell activities
• Customized text data display
• Customized time and date display
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repetitions
• Recording graphic images of X applications
• Logging changes in configuration files

Data storage tips

• Disk partition configuration
• Accessing partitions via UUID
• Filesystem configuration
• Filesystem creation and integrity checks
• Filesystem optimization via mount options
• Filesystem optimization via superblock
• Hard disk optimization
• Predicting hard disk failure using SMART
• Expanding usable 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
• Automatically encrypting files with eCryptfs
• Automatically mounting eCryptfs

Monitoring, controlling, and initiating 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 across files in a loop
• Launching programs from the GUI
• Customizing programs to be started
• Terminating processes
• Scheduling one-time tasks
• Scheduling regular tasks
• The Alt-SysRq key

System maintenance tips

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

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 image files
• Chroot systems
• 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
• 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 disks
• Data redundancy
• Data file recovery and forensic analysis
• Splitting large files into smaller ones
• Clearing file contents
• 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
• Invisible disk space consumption

Data security infrastructure

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