Diff increases when creating a csv

Hi guys,

I have an application mounted on a server on Ubuntu 16.04.4 LTS.

I often need to export CSV files to get some data form the DB so the app has a module for that. I’m using Laravel to create these files, everything works fine at this point but I have a container that runs my backend cronjobs (which one of them is responsible for creating the csv files) and every time I create one file the docker/aufs/diff folder increases a lot, usually taking all the server disk space.

I can manually restart the container and it frees disk space but I don’t feel it right that way, so my questions are, is the diff folder taking that much space a normal behavior??

Is there a way to automate a clean up every time that folder increases??

Any help is appreciated

Info:
Docker version 1.12.6,
Server: Ubuntu 16.04.4 LTS