Посмотреть, сколько занимает места на диске:
  docker system df

----
  
As of 1.13.0, see the new //prune// commands:

Remove all stopped containers:
  docker container prune
Remove all unused volumes:
  docker volume prune      
Remove unused images:
  docker image prune       
All of the above, in this order: containers, volumes, images:
  docker system prune