Why removing docker containers and images does not free up storage space on Windows? How to fix it?

Question

Problem:

As I download and run containers, they keep taking up more and more space. I found suggestions for cleaning up unused containers and images and I did so. Guess what? They eat up even more disk space!

What I found so far:

It has to do with .docker\machine\machines\default\disk.vmdk file. It only gets bigger!

Log of disk.vmdk:

                            size (MB) 1. with 2 images                1,376 2. downloading a new image X    ? 3. running X as Y               2,963 4. removing Y                   2,963 5. removing X                   3,106 6. removing all the images      3,126 

The only fix I found so far was running docker-machine rm default which removes the VM. The problem is that I have to download all the images again. There should be a better fix. Can someone explain:

1. What is going on?
2. How to fix it?

Answer 1

There are maintainance commands you can run on the more recent versions of Docker. They will free up space used by stopped containers, dangling images and dangling volumes:

docker container prune -f docker image prune -f docker volume prune -f