Debian Administration Training Course

Debian Distribution

What is Debian?

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

Console fundamentals

• Understanding the shell prompt
• Using the shell prompt within X
• The root account and root shell prompt (using su, sudo, and executing programs as root under X)
• GUI-based system administration tools
• Virtual consoles
• Exiting the command prompt
• Shutting down the system
• Restoring a functional console
• Recommended additional packages for beginners
• Creating an extra user account
• Configuring sudo

The filesystem

• Filesystem permissions
• Controlling permissions for new files: umask
• Group permissions for sets of users
• Timestamps
• 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
• MC's internal editor
• MC's internal viewer
• MC's auto-start features
• MC's FTP virtual filesystem

The basic Unix-like work environment

• The login shell
• Customizing bash
• Special keystrokes
• Using the pager
• Setting a default text editor
• Exiting vim
• Recording 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 utilities
• Regular expressions
• Substitution 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 ongoing upgrades
• Basics of the Debian archive
• Package dependencies
• The event flow of package management
• Initial responses to package management issues

Basic package management operations

• Comparing apt-get/apt-cache vs. aptitude
• Performing basic package management operations via the 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 names
• Browsing using regex matching
• Permanently purging removed packages
• Organizing auto/manual installation status
• Performing a system-wide upgrade

Advanced package management operations

• Advanced package management operations via command line
• Verifying installed package files
• Safeguards for package problems
• Searching package metadata

Debian package management internals

• Archive metadata
• 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
• The dpkg command
• The update-alternative command
• The dpkg-statoverride command
• The dpkg-divert command

Recovery from a broken system

• Incompatibility with old user configurations
• Conflicts between packages with overlapping files
• Fixing broken package scripts
• Rescuing with the dpkg command
• Recovering package selection data

Tips for package management

• Choosing Debian packages
• Packages from mixed archive sources
• Adjusting candidate versions
• Updates and Backports
• Automatic package download and upgrade
• Limiting APT download bandwidth
• Emergency downgrading
• Identifying the package uploader
• The equivs package
• Porting a package to the stable system
• Configuring an APT proxy server
• Small public package archives
• Recording and copying system configuration
• Converting or installing alien binary packages
• Extracting packages without dpkg
• Further reading for 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 each init script
• 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, 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 range
• Network device support

Modern network configuration for desktops

• GUI network configuration tools

Low-level network configuration

• Iproute2 commands
• Safe low-level network operations

Network optimization

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

Netfilter infrastructure

Network applications

The mail system

• Basics of modern mail services
• 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 filters

• Configuring maildrop
• Configuring procmail
• 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 non-standard SSH clients
• Setting up ssh-agent
• Shutting down the remote system 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 over the Internet
• X applications
• X office applications
• X utility applications

System tips

The screen program

• Use scenarios 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 graphical 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 checking
• Filesystem optimization via mount options
• Filesystem optimization via superblock
• Hard disk optimization
• 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 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 a process
• Setting 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
• Notifying 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 systems

• Virtualization tools
• Virtualization workflow
• Mounting virtual disk image files
• Chroot systems
• 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
• 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
• Dummy files
• Erasing an entire hard disk
• Erasing unused areas of a hard disk
• Undeleting files that are deleted but still open
• Searching all hard links
• Hidden disk space consumption

Data security infrastructure

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