ced4568andClaude Sonnet 5
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Adds all 6 ROOT 02 modules (Linux system administration, storage & filesystems, the Networking Mental Model, Linux network inspection, DNS & HTTP, Linux troubleshooting) — 37 activities, each with a real lesson, demonstration/guided exercise, knowledge check, hands-on Lab, and reflection. The Networking Mental Model module (M3) gets deliberately extra depth per its "critical module" designation, with no lab by design — conceptual mastery via knowledge check and guided exercise, matching root-05-m00's own precedent. Adds 6 new hands-on Linux/networking scenarios plus 2 MCQs: linux-service-inspection (inspects the platform's own real nginx without touching it — a genuinely safe, real service-inspection target that avoids ever risking the Lab's own connectivity), linux-service-lifecycle (start/ verify/stop a fully controllable service), linux-storage-inspection, linux-network-inspection (ip/ss/getent/curl, each framed as answering one specific diagnostic question), linux-dns-http-diagnosis (a genuine DNS-resolves-but-wrong-port failure, diagnosed and fixed), and linux-troubleshooting-framework (a real missing-config-file failure, resolved via the RootNode Observe/Evidence/Hypothesis/Test/Repair/Validate/Prevent framework). All tested end-to-end via the real scenario-validation API, including negative tests confirming they fail when unsolved. Wires rootnode-linux-networking-assessment (2 required + 4 random-draw scenarios) using the existing Phase 3B assessment engine. Co-Authored-By: Claude Sonnet 5 <[email protected]>
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Reflection: "It's Probably the Logs" Is a Guess, Not a Diagnosis
Reflection questions
- Before measuring, which of the three directories in this module's Lab did you guess would be largest? Were you right?
- Why does "persistent vs. temporary" matter enough to be worth memorizing as a question you ask about EVERY piece of data, not just during a storage module?
Real Ops takeaway
Guessing which directory is consuming disk space, without measuring, is exactly the kind of
assumption that wastes real incident-response time. du, applied progressively (broad, then
narrow), replaces guessing with evidence in seconds. And the persistent-vs-temporary question
you just practiced is the exact same question you'll ask again in ROOT 04 about container data,
and again much later about Kubernetes storage — a question worth internalizing now, cheaply,
rather than learning the hard way after data you assumed would persist didn't.
This module is complete. Continue to the next module.
Instructor Notes
Discussion questions for a live classroom: question 1 works well as a quick poll before revealing the real answer — the mismatch between guesses and reality reinforces the lesson better than stating it directly.
Approximate timing: 5-8 minutes live discussion; 5 minutes self-paced writing.