Minimserver in Docker Container Keeps Writing To Disk

[bubbleguuum]

Had the same problem reported by a user of BubbleUPnP Server, which when run as a docker container was preventing his spinning hard drive to go to sleep.

It was not easy to troubleshoot, but long story short:

- obviously, MinimServer must not write to disk at regular intervals: logs or something else

- OpenJDK writes performance data to disk (in /tmp) at regular interval. This must be disabled with "-XX:-UsePerfData" passed as JVM startup argument.

- Docker does its own writing to disk on host. If the running docker image has a periodic health check declared its Dockerfile, the results are written to file config.v2.json (on host).
It must be disabled with --no-healthcheck passed to docker at container creation (docker create) or running (docker run).
If MinimServer writes regularly to stdout, Docker will log that output to file on host. This can be disabled with "--log-driver none" passed to docker