Episode 51 — Volumes and storage: persistence, mapping, overlay concepts, SELinux context awareness
Linux+ tests container storage because persistence is where many real container deployments go wrong. This episode explains how containers use a layered filesystem model: an image provides read-only layers, a container adds a writable layer, and volumes or bind mounts provide persistent storage outside the container’s ephemeral write layer. You’ll learn why this matters on the exam: if data must survive container recreation, it belongs in a volume or an intentionally mapped host path, not inside the container’s writable layer. We also introduce overlay concepts at a practical level, focusing on the boundary between what is part of the image, what is transient at runtime, and what is explicitly persisted, because many questions hinge on that distinction.
we connect storage mapping to troubleshooting and security controls, including SELinux context awareness. You’ll practice diagnosing symptoms like “data disappeared after restart,” “permission denied on mounted paths,” or “application can’t write to its data directory” by verifying what is actually mounted and what context or ownership is enforced. We also cover the operational tradeoffs between volumes and bind mounts: predictability and portability versus tight host coupling and risk of exposing sensitive host paths. Finally, you’ll learn best practices aligned with exam intent: define storage mappings explicitly, validate persistence by recreating the container, and treat security controls like SELinux contexts as part of the storage design so enforcement does not look like random breakage during deployment. Produced by BareMetalCyber.com, where you’ll find more cyber audio courses, books, and information to strengthen your educational path. Also, if you want to stay up to date with the latest news, visit DailyCyber.News for a newsletter you can use, and a daily podcast you can commute with.
