ced4568andClaude Sonnet 5
73cea1ba1d
Two new PARTIAL modules, moving ROOT 08 off PLANNED for the first time: root-08-m01-storage-fundamentals — ephemeral vs. persistent storage, PV/PVC/StorageClass. Lesson + knowledge check + real Labs (emptydir-pod, pv-pvc-mount, pvc-dynamic-task, storageclass-mcq). root-08-m02-scheduling-resource-governance — how the scheduler places Pods and how quotas/limits/priority/disruption budgets shape that placement. Lesson + knowledge check + real Labs (node-label-selector, node-taint-toleration, pod-affinity-mcq, priority-class-task, pod-disruption-budget-task, resource-quota-ns, limitrange-task). cluster-upgrade-mcq and etcd-backup-mcq deliberately left unwired — ROOT 11/DevOps territory, out of this phase's scope, not overlooked. Co-Authored-By: Claude Sonnet 5 <[email protected]>
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Knowledge Check: Storage Fundamentals
1. Two containers in the same Pod need to share files with each other, but nothing needs to survive the Pod being replaced. What's the simplest correct choice?
Answer: emptyDir — shared within the Pod, deliberately temporary, exactly matching the
requirement. Reaching for a PV/PVC here would be more machinery than the problem needs.
2. A Pod using a PVC is deleted and a new Pod is created referencing the SAME PVC. What happens to the data?
Answer: It's preserved. The PVC and its bound PV exist independently of any specific Pod — the
new Pod picks up exactly where the data was left, which is the entire reason to use persistent
storage instead of emptyDir for anything that needs to outlive a single Pod's lifetime.
3. True or false: a Pod's manifest must specify exactly which PersistentVolume backs its storage request.
Answer: False. A Pod references a PVC (a request), not a PV directly — the binding between PVC and an actual PV is resolved separately, which is exactly the indirection that lets the same Pod manifest work regardless of which physical storage ends up behind it.
4. What does a StorageClass's reclaim policy actually control, and why would a team choose
Retain over Delete for a production database's storage?
Answer: It controls what happens to the underlying storage after its PVC is deleted. Retain
keeps the data around for manual recovery instead of immediately destroying it — a safety
margin against an accidental kubectl delete pvc on something genuinely important, at the cost
of needing manual cleanup later.
Instructor Notes
Facilitation: Question 2 is worth confirming lands correctly — it's the single fact that justifies the entire PV/PVC indirection existing at all.
Approximate timing: 5 minutes.