I think I discovered the faulty app which causes the dumps… It’s my own fault as I activated a not (yet) fitting app for NC31x… Snappy mail. So it seems that everytime I’d access that app (to read my mails on several accounts) the dump-section fills up with coredumps.
as for now I’m just deleting all coredumps after 60 min via a cronjob. I know thats not the way it should be but right now I have no time to act different than quick & dirty