Is there any way for turn on logging for accessed files in Seafile Server Open Source version? read, write, delete ?
unfortunately this is not possible since this is a feature from the pro version. There are pricing models for 3 users (free) and 9 users for only $100 - please see: https://www.seafile.com/en/product/private_server/
Maybe this is a solution for you.
Anyway fortunately price for 9 users is not so bad for us - people from East Europe (Poland) who don’t have so much money