Container filesystem is ephemeral in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does it mean that a container's filesystem is ephemeral?

It means that any changes made inside the container's filesystem are temporary and will be lost when the container is removed.

beginner

How can you keep data persistent when using containers?

By using volumes or bind mounts to store data outside the container's ephemeral filesystem.

beginner

What happens to files created inside a container if the container is deleted?

All files created inside the container are deleted along with the container unless they are stored in a volume or external storage.

intermediate

Why is the ephemeral nature of container filesystems useful?

It allows containers to be lightweight and easily replaceable without worrying about leftover data or state.

beginner

What Docker command can you use to create a volume for persistent data?

docker volume create <volume_name>

What happens to data inside a Docker container's filesystem when the container is removed?

A Data is automatically saved to the host

B Data is lost unless saved to a volume

C Data is backed up by Docker

D Data remains permanently inside the container

Container filesystems are ephemeral, so data is lost unless stored in volumes or external storage.

Which Docker feature helps keep data persistent beyond the container's life?

A Volumes

B Ephemeral filesystem

C Docker images

D Docker networks

Volumes store data outside the container, making it persistent.

If you delete a container, what happens to its ephemeral filesystem?

A It is saved automatically

B It is moved to a volume

C It is deleted along with the container

D It becomes read-only

The ephemeral filesystem is removed when the container is deleted.

Why might ephemeral filesystems be helpful in development?

A They allow quick resets by removing containers

B They save data permanently

C They increase container size

D They slow down container startup

Ephemeral filesystems let you start fresh easily by deleting containers.

Which command creates a Docker volume?

A docker volume run mydata

B docker create volume mydata

C docker volume start mydata

D docker volume create mydata

The correct syntax to create a volume is 'docker volume create '.

Explain why container filesystems are called ephemeral and how this affects data storage.

Think about what happens to files inside a container after it stops.

Describe how you would keep important data safe when working with Docker containers.

Consider how to separate data from the container's temporary storage.