From the author of the jsonDB service for OH2 (@chris):
You can configure the Json Storage in PaperUI->Configuration->System->Json Storage
Here you can find more info on how the jsonDB works on OH2:
a) http://docs.openhab.org/administration/jsondb.html
b) Replacement of mapdb by jsondb
c) Add content to jsondb.md by AngelosF · Pull Request #281 · openhab/openhab-docs · GitHub (easier to read version: Here)
I need to implement (c) into (a)… I still haven’t done that and @ThomDietrich will shoot me soon