Couldn't create subfolders

Dear jacobalberty,
I've tried your docker image on Synology, 
and linked a NAS folder to /config. 
It seems to work a little bit:
etc and logs are created,
but when I take a look in the Docker protocol,
it states it couldn't create some sub-subfolder,
beneath the subfolder "state" (which is not created).
Already tried to give the NAS folder more read/write rights,
but it did not help.
