Diagnose docker container size

README.md

Sometimes there's a problem where containers taking up all space. The following checklist helps with diagnosing what is the root cause of that.

1. Basic commands to check docker status and consumed size

docker system df
docker system df -v
docker container ls -s

2. Check docker container log size

container=34443add1c1c
du -h $(dirname $(docker inspect "$container" --format '{{ .LogPath }}'))

If this folder contains large files, most likely container produces massive amount of logs on stdout. A simple solution is to review what's being logger or set a cap to limit log files, for example in docker-compose:

    logging:
      driver: "json-file"
      options:
        max-size: "100m"
        max-file: "10"

3. Check docker container diff folder (whether there's any additional file structure on writable layer)

du -h $(dirname $(docker inspect "$container" --format '{{ .GraphDriver.Data.MergedDir }}'))/diff

References:

• https://forums.docker.com/t/docker-containers-taking-up-all-space-over-time/137291