Managing Volumes

Auto-Creation of Volumes

What happens if you try to start a container and attach it to a volume that doesn’t exist?

# Assuming 'new-vol' doesn't exist
docker run -d -p 3001:2368 -v new-vol:/var/lib/ghost ghost

It turns out the -v new-vol:/var/lib/ghost flag will bind to a new-vol volume if it exists, but otherwise, it creates it automatically!

Deleting Volumes and Cleaning Up

When you’re done, you’ll want to save space on your host machine by deleting the volume and the container.

1. First, use docker ps -a to see all containers (even stopped ones).
2. Stop and remove the containers using docker stop and docker rm.
3. Use docker volume ls to find your volumes.
4. Remove the volume using docker volume rm.

# Stop and remove container
docker stop CONTAINER_ID
docker rm CONTAINER_ID

# Remove the volume
docker volume rm my-vol

Note: You cannot remove a volume that is currently in use by a container, even if the container is stopped. You must remove the container first.