Volumes for persistent data in Docker - Cheat Sheet & Quick Revision

Recall & Review

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What is a Docker volume?

A Docker volume is a special storage area managed by Docker that keeps data outside the container's writable layer. It helps data persist even if the container is deleted or recreated.

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How do you create a Docker volume?

You create a Docker volume using the command: docker volume create my_volume. This makes a new volume named 'my_volume' ready to use.

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How do you attach a volume to a container?

Use the docker run command with the -v option: docker run -v my_volume:/data my_image. This mounts the volume 'my_volume' inside the container at the path '/data'.

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Why use volumes instead of container file system for data?

Because container file systems are temporary and deleted when the container stops. Volumes keep data safe and available even if containers are removed or updated.

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How can you list all Docker volumes on your system?

Run the command docker volume ls. It shows all volumes created and available on your Docker host.

What happens to data stored inside a Docker container's file system when the container is deleted?

A The data is lost unless stored in a volume

B The data is automatically saved to the host

C The data is backed up by Docker

D The data is moved to another container

Data inside a container's file system is deleted when the container is removed. Volumes are needed to keep data persistent.

Which command creates a new Docker volume named 'data_vol'?

A docker volume create data_vol

B docker create volume data_vol

C docker volume new data_vol

D docker volume add data_vol

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

How do you mount a volume 'myvol' to '/app/data' inside a container?

A docker run -v /app/data:myvol my_image

B docker run -mount myvol:/app/data my_image

C docker run --volume /app/data:myvol my_image

D docker run -v myvol:/app/data my_image

The correct syntax is '-v volume_name:container_path'.

Which command lists all Docker volumes on your system?

A docker volume show

B docker volumes list

C docker volume ls

D docker list volumes

'docker volume ls' is the correct command to list volumes.

Why are Docker volumes preferred for storing database files?

A They encrypt data inside the container

B They keep data safe even if containers are removed

C They automatically backup data to the cloud

D They make containers run faster

Volumes keep data persistent and safe beyond the life of a container, which is important for databases.

Explain what Docker volumes are and why they are important for persistent data.

Think about what happens to data when a container is deleted.

Describe the steps and commands to create a Docker volume and use it in a container.

Focus on commands and how to connect volume to container.