# Knowledge Check: Container Storage

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**1. By default, what happens to data written inside a running container when that container is
destroyed?**

*Answer:* It's lost permanently — a container's writable layer is disposable by default; nothing
persists unless a volume or bind mount was explicitly configured.

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**2. What's the actual difference between a bind mount and a named volume?**

*Answer:* A bind mount connects a specific HOST filesystem path directly into the container
(tightly coupled to that host's exact layout). A named volume is storage Docker manages
independently of any specific host path, making it more portable and the production-appropriate
choice.

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**3. Does `docker stop` (without removing) test whether a container's data actually persists?**

*Answer:* No — stopping doesn't touch the writable layer at all. Only fully removing
(`docker rm`) and recreating the container is a real test of persistence.

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**4. What Kubernetes concept is this module's volume idea the direct foundation for?**

*Answer:* PersistentVolume/PersistentVolumeClaim — the same persistence concept, generalized
across an entire cluster instead of one machine.

## Instructor Notes

**Facilitation:** Question 3 is worth emphasizing — it's a genuine, common mistake in verifying
persistence claims.

**Approximate timing:** 5 minutes.