Docker container size explosion

One of my docker hosts died and after some investigation I discovered the disk was full and don’t really understand why or how to resolve it given the dockers themselves are small.

I have grabbed screens from the file system and the docker output to show what I mean.

docker 2

docker 1

  1. I haven’t been able to work out which container this large file is. How do I do this?
  2. How do I shrink / reclaim this space?
  3. Is it possible to set a docker container size limits and alerts to stop the entire host crashing again?