image is being used by stopped container

Question

I am trying to delete a docker container by this command:

docker rmi 

Obviously, I have replaced the Image-Id by the Id I get u

Answer 1

If the goal is to reclaim disk space, another approach not yet mentioned is to use docker system prune. It will print a warning which should be heeded:

WARNING! This will remove:
  - all stopped containers
  - all networks not used by at least one container
  - all dangling images
  - all dangling build cache

This will not delete named images, but will purge intermediate unnamed images. Depending on the sizes of containers you're using, this can save a considerable amount of disk space.