Check the Running Docker
Understand how Docker uses a read-only image with thin read-write layers for containers. Learn to check if Docker is running by verifying the client, server, and daemon status. This lesson helps you diagnose common Docker startup issues and grasp container image layering.
Images and containers
We can start multiple containers from a single image. The image is read-only in this relationship, but each container is read-write. As shown in the figure below, Docker accomplishes this by creating a thin read-write layer for each container and placing it on top of the shared image.
Container R/W layers
In the figure above, each container has its own thin R/W layer but shares the same image. The containers can see and access the files and apps ...