Docker Storage & Volumes Internals: Understanding Layers, OverlayFS & Persistence

Short summary

Docker storage uses OverlayFS to stack immutable read-only image layers with a thin writable container layer, implementing copy-on-write for efficient storage and fast container startup. Volumes provide persistent Docker-managed storage that survives container deletion; bind mounts offer host-path flexibility for development. Optimize disk usage by understanding layer deduplication, removing dangling images and build cache with docker system prune, and consistently using volumes for production data and stateful services.

• •Docker uses OverlayFS to layer read-only image layers with a writable container layer using copy-on-write mechanics
• •Volumes persist data independently and survive container deletion; bind mounts map host paths for development flexibility
• •Optimize disk usage with proper image cleanup, layer deduplication, and docker system prune commands

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