This is a comprehensive training course for administering Debian GNU/Linux operating system.

It is always delivered on the current version of Debian.

Debian Distribution

What is Debian?

• Choosing Debian version
• Debian support and help
• Debian community

Console basics

• The shell prompt
• The shell prompt under X
• The root account and root shell prompt (su, sudo, running programs as root under X)
• GUI system administration tools
• Virtual consoles
• How to leave the command prompt
• How to shutdown the system
• Recovering a sane console
• Additional package suggestions for the newbie
• An extra user account
• sudo configuration

The filesystem

• Filesystem permissions
• Control of permissions for newly created files: umask
• Permissions for groups of users (group)
• Timestamps
• Links
• Named pipes (FIFOs)
• Sockets
• Device files
• Special device files
• procfs and sysfs

Midnight Commander (MC)

• Customization of MC
• Starting MC
• File manager in MC
• Command-line tricks in MC
• The internal editor in MC
• The internal viewer in MC
• Auto-start features of MC
• FTP virtual filesystem of MC

The basic Unix-like work environment

• The login shell
• Customizing bash
• Special key strokes
• The pager
• Setting a default text editor
• How to quit vim
• Recording the shell activities
• Basic Unix commands

The simple shell command

• Command execution and environment variable
• "$LANG" variable
• "$PATH" variable
• "$HOME" variable
• Command line options
• Shell glob
• Return value of the command
• Typical command sequences and shell redirection
• Command alias

Unix-like text processing

• Unix text tools
• Regular expressions
• Replacement expressions
• Global substitution with regular expressions
• Extracting data from text file table
• Script snippets for piping commands

Debian package management

Debian package management prerequisites

• Package configuration
• Basic precautions
• Life with eternal upgrades
• Debian archive basics
• Package dependencies
• The event flow of the package management
• First response to package management troubles

Basic package management operations

• apt-get/apt-cachevs.aptitude
• Basic package management operations with the commandline
• Interactive use of aptitude
• Key bindings of aptitude
• Package views under aptitude
• Search method options with aptitude
• The aptitude regex formula
• Dependency resolution of aptitude
• Package activity logs

Examples of aptitude operations

• Listing packages with regex matching on package names
• Browsing with the regex matching
• Purging removed packages for good
• Tidying auto/manual install status
• System wide upgrade

Advanced package management operations

• Advanced package management operations with commandline
• Verification of installed package files
• Safeguarding for package problems
• Searching on the package meta data

Debian package management internals

• Archive meta data
• Top level "Release" file and authenticity
• Archive level "Release" files
• Fetching of the meta data for the package
• The package state for APT
• The package state for aptitude
• Local copies of the fetched packages
• Debian package file names
• The dpkg command
• The update-alternative command
• The dpkg-statoverride command
• The dpkg-divert command

Recovery from a broken system

• Incompatibility with old user configuration
• Different packages with overlapped files
• Fixing broken package script
• Rescue with the dpkg command
• Recovering package selection data

Tips for the package management

• How to pick Debian packages
• Packages from mixed source of archives
• Tweaking candidate version
• Updates and Backports
• Automatic download and upgrade of packages
• Limiting download bandwidth for APT
• Emergency downgrading
• Who uploaded the package?
• The equivs package
• Porting a package to the stable system
• Proxy server for APT
• Small public package archive
• Recording and copying system configuration
• Converting or installing an alien binary package
• Extracting package without dpkg
• More readings for the package management

The system initialization

• An overview of the boot strap process
• BIOS, boot loader, mini-Debian system
• The meaning of the runlevel
• The configuration of the runlevel
• The runlevel management example
• The default parameter for each init script
• The hostname
• The filesystem
• Network interface initialization
• Network service initialization
• The system message
• The kernel message
• The udev system
• The kernel module initialization

Authentication and Security

• Normal Unix authentication
• Managing account and password information
• Good password
• Creating encrypted password
• PAM and NSS
• Configuration files accessed by the PAM and NSS
• The modern centralized system management
• "Why GNU su does not support the wheel group"
• Stricter password rule
• Other access controls
• sudo
• SELinux, Apparmor
• Restricting access to some server services
• Security of authentication
• Secure password over the Internet
• Secure Shell
• Extra security measures for the Internet
• Securing the root password

Network setup

The basic network infrastructure

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

The modern network configuration for desktop

• GUI network configuration tools

The 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
• The mail configuration strategy for workstation

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
• Redeliver mbox contents

POP3/IMAP4 server

The remote access server and utility (SSH)

• Basics of SSH
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Dealing with alien SSH clients
• Setting up ssh-agent
• How to shutdown the remote system on SSH
• Troubleshooting SSH

Other network application servers

Other network application clients

The diagnosis of the system daemons

The X Window System

• Setting up desktop environment
• The server/client relationship
• The X server
• Starting the X Window System
• Starting X session with gdm
• Customizing the X session (classic method)
• Customizing the X session (new method)
• Connecting a remote X client via SSH
• Secure X terminal via the Internet
• X applications
• X office applications
• X utility applications

System tips

The screen program

• The use scenario for screen(1)
• Key bindings for the screen command

Data recording and presentation

• The log daemon
• Log analyzer
• Recording the shell activities cleanly
• Customized display of text data
• Customized display of time and date
• Colorized shell echo
• Colorized commands
• Recording the editor activities for complex repeats
• Recording the graphic image of an X application
• Recording changes in configuration files

Data storage tips

• Disk partition configuration
• Accessing partition using UUID
• Filesystem configuration
• Filesystem creation and integrity check
• Optimization of filesystem by mount options
• Optimization of filesystem via superblock
• Optimization of hard disk
• Using SMART to predict hard disk failure
• Expansion of usable storage space via LVM
• Expansion of usable storage space by mounting another partition
• Expansion of usable storage space using symlink
• Expansion of usable storage space using aufs

Data encryption tips

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

Monitoring, controlling, and starting program activities

• Timing a process
• The scheduling priority
• The ps command
• The top command
• Listing files opened by a process
• Tracing program activities
• Identification of processes using files or sockets
• Repeating a command with a constant interval
• Repeating a command looping over files
• Starting a program from GUI
• Customizing program to be started
• Killing a process
• Scheduling tasks once
• Scheduling tasks regularly
• Alt-SysRq key

System maintenance tips

• Who is on the system?
• Warning everyone
• Hardware identification
• Hardware configuration
• System and hardware time
• The terminal configuration
• The sound infrastructure
• Disabling the screen saver
• Disabling beep sounds
• Memory usage
• System security and integrity check

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 system

• Virtualization tools
• Virtualization work flow
• Mounting the virtual disk image file
• Chroot system
• Multiple desktop systems

Data management

Sharing, copying, and archiving

• Archive and compression tools
• Copy and synchronization tools
• Idioms for the archive
• Idioms for the copy
• Idioms for the selection of files
• Backup and recovery
• Backup utility suites
• An example script for the system backup
• A copy script for the data backup
• Removable storage device
• Sharing data via network
• Archive media

The binary data

• Viewing and editing binary data
• Manipulating files without mounting disk
• Data redundancy
• Data file recovery and forensic analysis
• Splitting a large file into small files
• Clearing file contents
• Dummy files
• Erasing an entire hard disk
• Erasing unused area of an hard disk
• Undeleting deleted but still open files
• Searching all hardlinks
• Invisible disk space consumption

Data security infrastructure

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