Debian Administration Training Course

Debian Distribution

What is Debian?

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

Console fundamentals

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

The filesystem

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

Midnight Commander (MC)

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

The basic Unix-like work environment

• The login shell
• Customizing bash
• Special key combinations
• 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
• Standard command sequences and shell redirection
• Command aliases

Unix-like text processing

• Unix text utilities
• 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
• Living with continuous upgrades
• Debian archive fundamentals
• Package dependencies
• The event flow of package management
• Initial responses to package management issues

Basic package management operations

• apt-get/apt-cache vs. aptitude
• Basic package management operations 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 using regex matching on names
• Browsing via regex matching
• Completely purging removed packages
• Tidying up auto/manual install status
• System-wide upgrades

Advanced package management operations

• Advanced package management operations via the command line
• Verifying installed package files
• Mitigating package issues
• 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 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 configurations
• Different packages with overlapping files
• Fixing broken package scripts
• Rescue using the dpkg command
• Recovering package selection data

Tips for package management

• How to select Debian packages
• Packages from mixed archive sources
• Adjusting candidate versions
• Updates and Backports
• Automatic package download and upgrade
• Limiting download bandwidth for APT
• Emergency downgrading
• Identifying the package uploader
• 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 a package without dpkg
• Further reading on package management

System initialization

• Overview of the boot strap process
• BIOS, boot loader, and mini-Debian system
• Meaning of the runlevel
• Configuring the runlevel
• Example of runlevel management
• 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"
• Stricter password rules
• Other access controls
• sudo
• SELinux, Apparmor
• Restricting access to specific server services
• Authentication security
• Secure passwords over the Internet
• Secure Shell
• Additional security measures for the Internet
• Securing the root password

Network setup

Basic network infrastructure

• Domain names
• Hostname resolution
• Network interface names
• Network address range for the LAN
• Network device support

Modern desktop network configuration

• GUI-based network configuration tools

Low-level network configuration

• Iproute2 commands
• Safe low-level network operations

Network optimization

• Finding the optimal MTU
• Setting the 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 filtering

• maildrop configuration
• procmail configuration
• Redelivering mbox contents

POP3/IMAP4 server

Remote access server and utility (SSH)

• SSH fundamentals
• Port forwarding for SMTP/POP3 tunneling
• Connecting without remote passwords
• Handling non-native SSH clients
• Configuring 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
• 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
• Secure 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

• The log daemon
• Log analyzers
• Cleanly recording shell activities
• Customized display of text data
• Customized display of time and date
• Colorized shell echo
• Colorized commands
• Recording editor activities for complex repeats
• Recording graphic images of X applications
• Tracking changes in configuration files

Data storage tips

• Disk partition configuration
• Accessing partitions using UUID
• Filesystem configuration
• Creating and checking filesystem integrity
• Optimizing filesystems via mount options
• Optimizing filesystems via superblock
• Hard disk optimization
• Predicting hard disk failure using SMART
• 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
• 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
• Looping commands over files
• Starting a program from the GUI
• Customizing the program to be started
• Terminating a process
• Scheduling one-time tasks
• Scheduling regular tasks
• Alt-SysRq key

System maintenance tips

• Checking who is on the system
• 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 the kernel source: 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
• 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 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
• Wiping an entire hard disk
• Erasing unused areas of a hard disk
• Undeleting deleted but still open files
• Finding all hardlinks
• Invisible disk space consumption

Data security infrastructure

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