Debian Linux Administration

Duration: 35 Hours (5 Days) Level: Intermediate to Advanced

Day 1: Ecosystem Fundamentals & The Shell Environment

Introduction to the Distribution (History, stability branches: Stable/Testing/Unstable, Social Contract).
Version Selection Strategy (Choosing the right release for servers vs. workstations).
Ecosystem Support Channels (Navigating documentation, mailing lists, Bug Tracking System, IRC/Discord communities).

Terminal Fundamentals (Shell prompts, distinctions between TTY and PTY, standard input/output).
Privileged Access Management (The root user, su vs. sudo workflows, graphical root limitations).
Session Management (Virtual consoles, clean exit strategies, system power states: shutdown/reboot).
Emergency Access (Regaining control of a frozen console, reset, SysRq basics).
User Management Basics (Adding users, initial environment setup).

Navigating the VFS (Understanding the directory tree: /, /home, /var, /etc).
Permission Models (Standard UGO permissions, chmod, chown).
Default Security Contexts (Understanding and setting umask).
Advanced File Concepts (Hard links vs. Symbolic links, timestamps).
Special File Types (Named pipes/FIFOs, Unix sockets, Block vs. Character devices).
Virtual Filesystems (Interacting with procfs and sysfs for system state).

MC Fundamentals (Installation, interface navigation, startup options).
File Management Operations (Copy, move, permissions, virtual FTP connection handling).
Built-in Tools (Internal viewer/editor, command execution within MC, sub-shell tricks).
Customization (Menu configuration, auto-start logic).

Environment Configuration (Login vs. non-login shells, .bashrc, .profile).
Variable Management ($PATH, $HOME, $LANG, and their impact on execution).
Command Line Efficiency (Aliases, history expansion, tab completion, key bindings).
Editor Proficiency (Setting default editors, basic vim survival and exit strategies).
Session Recording (Using script to log terminal output).

Stream Redirection (Piping |, standard error redirection 2>, return codes $?).
Globbing and Wildcards (Matching file patterns).
Text Manipulation Tools (Introduction to grep, sed, awk, cut).
Regular Expressions (Regex syntax, global substitution, data extraction patterns).
Scripting Basics (One-liners for batch processing and table extraction).

Package Management Logic (Repositories, sources.list, dependency resolution graphs).
High-Level Tools (apt-get vs. aptitude: interactive modes, search patterns, regex filters).
Operational Workflows (Updating, upgrading, installing, purging configs).
Maintenance & Troubleshooting (Fixing broken dependencies, tidying orphan packages, log analysis).
Release Management (Performing system-wide distribution upgrades).

The DPKG Backend (Direct .deb manipulation, file verification, installation without APT).
Metadata & Integrity (GPG signing, Release files, checksums, package state flags).
Advanced Configuration (update-alternatives for software versions, dpkg-divert, dpkg-statoverride).
Disaster Recovery (Recovering package selection lists, fixing corrupt install scripts).
Repository Management (Backports, pinning versions, limiting bandwidth, proxy configuration).

The Boot Sequence (BIOS/UEFI -> Bootloader -> Kernel -> Init).
Runlevel/Target Management (Understanding runlevels, init scripts, defaulting services).
Hardware Initialization (Kernel modules, udev device management, kernel messages dmesg).
System Identity (Hostname configuration, locale settings).

Partitioning Strategies (UUIDs, filesystems types, integrity checks fsck).
Volume Management (Extending storage via LVM, mounting options, superblock tuning).
Disk Health (SMART monitoring, predicting failures).
Encryption (LUKS/dm-crypt for partitions, eCryptfs for directories/swap).
Optimization (Using aufs, symlinking strategies for space management).

Network Stack Basics (Interfaces, IP addressing, DNS resolution).
Configuration Tools (GUI tools vs. iproute2 suite, ifup/ifdown).
Optimization & Tuning (MTU discovery and setting, TCP window scaling, basic Netfilter/IPTables logic).

Remote Administration (SSH) (Key management, ssh-agent, tunneling/port forwarding, config troubleshooting).
Email Infrastructure (MTA vs MUA, Exim4 overview, Mutt client, Procmail/Maildrop filtering).
Protocol Clients (POP3/IMAP implementations, interactions with alien clients).

User Security (Password aging, strict policies, encrypted hashes).
Authentication Subsystems (PAM and NSS configuration and workflow).
Access Control (Sudoers configuration, introduction to MAC: SELinux/AppArmor).
Network Security (Securing SSH, root login restrictions, firewalling services).

X Architecture (Server/Client model, network transparency).
Session Management (Display Managers gdm, starting sessions, environment variables).
Remote Graphics (X over SSH, X terminals).
Desktop Applications (Office suites, utilities, and lightweight alternatives).

Process Control (PS, TOP, signaling/killing processes, priority nice/renice).
Job Scheduling (cron for recurring tasks, at for one-time jobs).
System Visibility (Tracing syscalls, listing open files with lsof).
Logging (Syslog daemon, log rotation, analyzing logs with regex).

Kernel Compilation (Debian-way compilation, headers, patching).
Module Management (Compiling external modules, proprietary drivers).
Virtualization (Overview of tools, working with disk images, chroot environments).

Backup Strategies (Archive tools: tar/gzip/bzip2, rsync for synchronization).
Binary Analysis (Viewing/editing binary files, handling raw data).
Forensics & Recovery (Undeleting files, analyzing file headers, secure deletion/wiping).
Cryptography (GPG key management, signing, verifying file integrity with MD5/SHA).

Terminal Multiplexing (Deep dive into screen: detach/attach sessions, split screens).
System Audit (Hardware identification, memory usage analysis, sound subsystem config).
Legacy Support (Converting alien packages with alien, extracting without installing).