Linux¶

Portal | Tag Cloud | 118 assets across 45 topics

Fundamentals, shell, systemd, filesystems, memory, performance, hardening

Core Skills (Tier 1)¶

Start here — these are the topics a mid-level engineer uses weekly.

Linux Fundamentals — Topic Pack ×32, Exercise Set, Drill, Scenario ×2, Assessment, Reference, Case Study ×20
Bash / Shell Scripting — Topic Pack ×18, Exercise Set, Drill, Assessment, Reference
systemd — Topic Pack ×7, Runbook, Assessment, Case Study ×2
Package Management — Topic Pack ×3, Assessment
Linux Hardening — Topic Pack ×7
Linux Users & Permissions — Topic Pack
Linux Boot Process — Topic Pack
Linux Memory Management — Topic Pack, Runbook
Linux Logging — Topic Pack
rsync — Topic Pack
iptables & nftables — Topic Pack, Case Study
SSH Deep Dive — Topic Pack
systemctl & journalctl Deep Dive — Topic Pack
Disk & Storage Ops — Topic Pack
Environment Variables — Topic Pack
Pipes & Redirection — Topic Pack
tmux & screen — Topic Pack
Linux Signals & Process Control — Topic Pack, Runbook
tar & Compression — Topic Pack
Linux Text Processing — Topic Pack
eBPF — Topic Pack ×3
Linux Performance Tuning — Topic Pack ×4, Runbook
Kernel Troubleshooting — Topic Pack
Process Management — Topic Pack, Runbook ×2
Cron & Job Scheduling — Topic Pack
Debian & Ubuntu Ecosystem — Topic Pack ×2
Linux Distribution Comparison — Topic Pack
Inodes (alias → filesystems_storage)
Linux Ops Performance Triage — Topic Pack
Linux Ops Storage — Topic Pack
Linux Ops systemd — Topic Pack
Mounts & Filesystems (alias) — Topic Pack

All Content¶

📘 Topic Packs¶

Asset	Topics	Level	Time	Status
/proc Filesystem	Linux Fundamentals, Linux Performance Tuning, /proc Filesystem	L2	3h	solid
Advanced Bash for Ops	Bash / Shell Scripting, Linux Fundamentals	L1	5h	solid
Binary and Floats	Binary & Number Representation	L1	2h	solid
Cilium & eBPF Networking	eBPF	L2	4h	solid
Compliance & Audit Automation	Linux Hardening	L2	5h	solid
Cron & Job Scheduling	Bash / Shell Scripting, Cron & Job Scheduling, systemd	L1	4h	solid
Debian & Ubuntu Ecosystem	Debian & Ubuntu Ecosystem, Linux Fundamentals, Package Management	L1	6h	solid
Disk & Storage Ops	Disk & Storage Ops, Linux Fundamentals	L1	5h	solid
Edge & IoT Infrastructure	Linux Fundamentals	L2	4h	solid
Environment Variables	Bash / Shell Scripting, Environment Variables, Linux Fundamentals	L1	2h	solid
Fleet Operations at Scale	Bash / Shell Scripting	L2	5h	solid
Infrastructure Forensics	Linux Hardening	L2	5h	solid
Kernel Troubleshooting	Kernel Troubleshooting, Linux Fundamentals	L3	6h	solid
LDAP & Identity Management	Linux Hardening	L2	5h	solid
LPIC / LFCS Exam Preparation	Bash / Shell Scripting, Linux Fundamentals, LPIC / LFCS Exam	L2	30h	solid
Linux Boot Process	Linux Boot Process, Linux Fundamentals, systemd	L1	3h	solid
Linux Distribution Comparison	Debian & Ubuntu Ecosystem, Linux Distribution Comparison, Linux Fundamentals	L1	4h	solid
Linux Kernel Tuning	Linux Kernel Tuning, Linux Performance Tuning	L2	4h	solid
Linux Logging	Linux Fundamentals, Linux Logging, systemd	L1	4h	solid
Linux Memory Management	Linux Fundamentals, Linux Memory Management, Linux Performance Tuning	L1	4h	solid
Linux Ops	Bash / Shell Scripting, Linux Fundamentals, Package Management	L0	5h	solid
Linux Ops Storage	Linux Ops Storage	L1	2h	solid
Linux Ops Systemd	Linux Ops systemd	L1	2h	solid
Linux Performance Tuning	eBPF, Linux Fundamentals, Linux Ops Performance Triage	L2	7h	solid
Linux Signals & Process Control	Linux Fundamentals, Linux Signals & Process Control	L1	3h	solid
Linux Text Processing	Bash / Shell Scripting, Linux Text Processing	L1	3h	solid
Linux Users & Permissions	Linux Fundamentals, Linux Hardening, Linux Users & Permissions	L1	4h	solid
Make & Build Systems	Bash / Shell Scripting	L1	3h	solid
Mental Models (Core Concepts)	Linux Fundamentals	L0	4h	solid
Mounts Filesystems	Mounts & Filesystems (alias)	L1	2h	solid
Nix / NixOS	Nix / NixOS	L2	4h	solid
Package Management	Package Management	L1	2h	solid
Pipes & Redirection	Bash / Shell Scripting, Linux Fundamentals, Pipes & Redirection	L1	3h	solid
Process Management	Bash / Shell Scripting, Linux Fundamentals, Process Management	L1	4h	solid
RHCE (EX294) Exam Preparation	Bash / Shell Scripting, Linux Fundamentals, systemd	L2	40h	solid
Regex & Text Wrangling	Bash / Shell Scripting, Linux Fundamentals	L1	5h	solid
SELinux & AppArmor	Linux Fundamentals, Linux Hardening	L2	5h	solid
SELinux & Linux Hardening	Linux Hardening	L2	5h	solid
SSH Deep Dive	Linux Fundamentals, Linux Hardening, SSH Deep Dive	L1	4h	solid
Terminal Internals	Bash / Shell Scripting, Terminal Internals	L1	2h	solid
Virtualization	Linux Fundamentals	L2	5h	solid
awk: The Record/Field Processor	Bash / Shell Scripting	L1	2h	solid
cgroups & Linux Namespaces	cgroups & Linux Namespaces, Linux Fundamentals	L2	4h	solid
curl & wget	Linux Fundamentals	L1	3h	solid
eBPF & Modern Linux Observability	eBPF, Linux Fundamentals	L3	5h	solid
find	Bash / Shell Scripting	L1	3h	solid
grep & Regular Expressions	Bash / Shell Scripting	L1	4h	solid
iptables & nftables	iptables & nftables, Linux Fundamentals	L1	4h	solid
perf Profiling	perf Profiling	L2	2h	solid
rsync	Linux Fundamentals, rsync	L1	3h	solid
sed: The Stream Editor	Bash / Shell Scripting	L1	2h	solid
strace	strace	L1	2h	solid
systemctl & journalctl Deep Dive	Linux Fundamentals, systemctl & journalctl Deep Dive, systemd	L1	4h	solid
tar & Compression	Linux Fundamentals, tar & Compression	L1	2h	solid
tmux & screen	Linux Fundamentals, tmux & screen	L1	2h	solid
xargs	Bash / Shell Scripting	L1	3h	solid

🏋️ Exercise Sets¶

Asset	Topics	Level	Time	Status
Bash Exercises (Quest Ladder) (CLI)	Bash / Shell Scripting, Linux Fundamentals	L0	8h	solid

⚡ Drills¶

Asset	Topics	Level	Time	Status
Linux Ops Drills	Bash / Shell Scripting, Linux Fundamentals	L0	30m	solid

🎯 Scenarios¶

Asset	Topics	Level	Time	Status
Adversarial Interview Gauntlet (30 sequences)	Linux Fundamentals	L2	15h	solid
Interview: Linux Server Slow	Linux Fundamentals	L1	15m	solid

📋 Runbooks¶

Asset	Topics	Level	Time	Status
Runbook: High CPU (Runaway Process)	Linux Performance Tuning, Process Management	L1	15m	solid
Runbook: OOM Killer Activated	Linux Memory Management	L1	15m	solid
Runbook: Systemd Service Crash Loop	systemd	L1	15m	solid
Runbook: Zombie Processes Accumulating	Linux Signals & Process Control, Process Management	L2	15m	solid

📝 Assessments¶

Asset	Topics	Level	Time	Status
Skillcheck: Bash	Bash / Shell Scripting	L0	30m	solid
Skillcheck: Linux Fundamentals	Linux Fundamentals, Package Management, systemd	L0	30m	solid

📎 References¶

Asset	Topics	Level	Time	Status
Track: Foundations	Bash / Shell Scripting, Linux Fundamentals	L0	20h	solid

🔍 Case Studys¶

Asset	Topics	Level	Time	Status
Case Study: Ansible Playbook Hangs — SSH Agent Forwarding Blocked by Firewall	iptables & nftables	L2	30m	solid
Case Study: CI Pipeline Fails — Docker Layer Cache Corruption	Linux Fundamentals	L2	30m	solid
Case Study: Container Vuln Scanner False Positive Blocks Deploy	Linux Fundamentals	L2	30m	solid
Case Study: Disk Full Root Services Down	Linux Fundamentals	L1	30m	solid
Case Study: Disk Full — Runaway Logs, Fix Is Loki Retention	Linux Fundamentals	L2	30m	solid
Case Study: HPA Flapping — Metrics Server Clock Skew, Fix Is NTP	Linux Fundamentals	L2	30m	solid
Case Study: Inode Exhaustion	Linux Fundamentals	L1	30m	solid
Case Study: Job Queue Backlog — Worker Pod CPU Throttled by cgroup	Linux Fundamentals	L2	30m	solid
Case Study: Kernel Soft Lockup	Linux Fundamentals	L2	30m	solid
Case Study: OOM Killer Events	Linux Fundamentals	L2	30m	solid
Case Study: Runaway Logs Fill Disk	Linux Fundamentals	L1	30m	solid
Case Study: SELinux Denying Service	Linux Fundamentals	L1	30m	solid
Case Study: Systemd Service Flapping	systemd	L1	30m	solid
Case Study: Terraform Apply Fails — State Lock Stuck, DynamoDB Throttle	Linux Fundamentals	L2	30m	solid
Case Study: Time Sync Skew Breaks App	Linux Fundamentals	L2	30m	solid
Case Study: Zombie Processes Accumulating	Linux Fundamentals	L1	30m	solid
Ops Archaeology: The Container That Exits Immediately	Linux Fundamentals	L1	30m	solid
Ops Archaeology: The Gateway That Returns 502	Linux Fundamentals	L1	30m	solid
Ops Archaeology: The Job That Succeeded Wrong	Linux Fundamentals	L2	30m	solid
Ops Archaeology: The Replica That Fell Behind	Linux Fundamentals	L2	30m	solid
Ops Archaeology: The Service That Won't Start	Linux Fundamentals, systemd	L1	30m	solid
Ops Archaeology: The Slow Death Nobody Noticed	Linux Fundamentals	L2	30m	solid