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ced4568andClaude Sonnet 5 e007bcf000 feat(root02): author Linux Administration & Networking
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]>
2026-08-26 17:07:46 -05:00

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Markdown

# Guided Exercise: Narrow Down a Disk Problem on Paper
This is a paper exercise — commit to a plan before running commands in the Lab.
## Your task
`df -h /` shows the root filesystem is 95% full. You have three suspect directories:
`/var/log`, `/srv/cache`, and `/home`. Write the exact sequence of `du` commands you'd run to
find the actual culprit, narrowing your search efficiently rather than checking everything with
maximum depth immediately.
## A worked shape to check yourself against
```
du -sh /var/log /srv/cache /home
```
— one command, comparing all three top-level suspects at once. Whichever is largest, THEN
narrow further into it specifically (e.g. `du -sh /srv/cache/*` if that one's the culprit) rather
than deep-diving into all three from the start — this mirrors Module 1's "cheapest, fastest-
answering question first" principle.
## Instructor Notes
**Facilitation:** Point out that running `du -sh` separately three times versus once with all
three paths produces the same information — the point isn't syntax, it's the "compare broadly,
then narrow" strategy.
**Approximate timing:** 8-10 minutes live discussion; 5 minutes self-paced.