🐧 Linux Mastery & Systems Administration: Complete Curriculum Index

Welcome to the Linux Mastery and Systems Administration documentation series. This collection is structured as an end-to-end, progressive curriculum spanning foundational filesystem concepts, process supervision, storage architecture, enterprise networking, container internals, and defensive security.

Every guide in this series strictly follows a two-part learning format:

  • ⚡ Quick Dive: Executive summaries, quick-reference tables, and copy-paste one-liners for instant lookup.
  • 📖 Extended Guide: Deep technical breakdowns, underlying operating system mechanics (inodes, kernel tables, signals, cryptographic handshakes), practical examples, and production best practices.

📚 Complete Curriculum Roadmap

Part 1: Filesystem & File Operations

# Guide Primary Topics Covered
01 Linux File System Overview FHS 3.0 hierarchy, VFS architecture, Inodes & Superblocks, /etc/fstab mount options, ext4/XFS/Btrfs, and storage diagnostics.
02 Directory Navigation pwd (-P vs -L), relative vs. absolute paths, cd, mkdir (nested trees & brace expansion), rmdir, and the directory stack (pushd, popd, dirs).
03 Listing Files ls anatomy (-lahF), metadata column breakdown, wildcards & globbing, directory tree visualizations (tree), and modern alternatives (eza).
04 File Management cp (archive mode -a), mv atomicity, safe rm practices, touch timestamps, hard vs. symbolic links (inode mechanics), stat, and rsync.
05 File Viewing & Text Manipulation Sequential viewers (cat, tac, nl), interactive pagers (less), slice tools (head, tail -F), stream processing (cut, paste, tr, sort, uniq, wc, tee), and printf.
06 File Search & Comparison File discovery (find -exec ... {} +, locate, fd), content search (grep, ripgrep, sed), and difference analysis (diff -u, cmp, comm, patch).

Part 2: Security, Permissions & Access Control

# Guide Primary Topics Covered
07 Linux File Permissions Numeric/octal vs. symbolic chmod, directory permission nuances, special bits (SUID, SGID, Sticky Bit), default umask, POSIX ACLs (getfacl/setfacl), and attributes (chattr +i).
08 User, Groups & Ownership User identity (whoami, id, w), account databases (/etc/passwd, /etc/shadow, /etc/group), account management (useradd, usermod -aG, userdel), chown/chgrp, and sudo delegation via visudo.
18 Security Hardening, Audit & SELinux CIS benchmarks, Linux Audit Framework (auditd, ausearch), Pluggable Authentication Modules (PAM), fail2ban, and Mandatory Access Control (SELinux & AppArmor).

Part 3: Systems Administration, Storage & Services

# Guide Primary Topics Covered
09 File Compression & Archiving Multi-file archiving (tar), single-file compressors (gzip, bzip2, xz, zstd), parallel acceleration (pigz), cross-platform formats (zip, 7z), and SHA-256 verification.
10 Systems Administration & Diagnostics Process monitoring (ps aux, htop), Unix signals (SIGTERM, SIGKILL, SIGHUP), memory & hardware stats (free, vmstat, iostat), systemd & journalctl, modern networking (ip, ss, dig, ufw), and job control (nohup, crontab).
13 Package Management & Repositories APT (Debian/Ubuntu), DNF/RPM (RHEL), APK (Alpine), Pacman (Arch), managing GPG keyrings, package holds, and compiling from source (make, cmake).
14 Storage Partitioning & LVM GPT/MBR partition tables, parted/fdisk, Logical Volume Management (LVM: PV, VG, LV, dynamic live expansion, snapshots), swap files, and software RAID (mdadm).
15 Systemd Units, Timers & Journald Authoring custom .service files, restart policies, drop-in overrides (systemctl edit), .timer scheduling (modern cron replacement), and log retention with journalctl.
17 Performance Tuning & Kernel Limits Kernel tuning via /etc/sysctl.d/ (swappiness, TCP buffers, dirty ratios), process niceness (nice, ionice), resource limits (ulimit, limits.conf), and performance profiling.

Part 4: Networking, Remote Access & Containers

# Guide Primary Topics Covered
11 Deep Dive into SSH Cryptographic handshakes, Ed25519 key generation, ssh-agent, ~/.ssh/config jump hosts & multiplexing (ControlMaster), local/remote/dynamic tunneling, and /etc/ssh/sshd_config hardening.
16 Advanced Networking & Firewalls Policy routing (ip route), DNS architecture (systemd-resolved), stateful packet filtering (nftables, iptables), deep packet inspection (tcpdump), and Linux bridges/veth pairs.
19 Containers, Namespaces & Cgroups Linux Namespaces (Mount, PID, Net, IPC, UTS, User), Control Groups (cgroups v2 quotas), chroot/unshare, OverlayFS union mounting, and rootless container security.

Part 5: Automation & Terminal Productivity

# Guide Primary Topics Covered
12 Bash Scripting & Automation Production scripting standards (set -euo pipefail), parameter expansions, conditionals ([[ ... ]]), loops, functions, argument parsing (getopts), signal traps, and temp file management.
20 Terminal Multiplexing & Editor Productivity tmux persistent sessions, pane management, custom .tmux.conf, Vim/Neovim modal editing essentials, GNU Readline shell shortcuts, and modern CLI tools (fzf, zoxide, bat).