I cannot resolve this problem for days. I've installed nginx on the latest ubuntu server on virtualbox. I have a shared virtualbox folder which contains the web root. The owner of web root is root and its group is vboxsf. I've added www-data user to the vboxsf group and verified it via "groups www-data". The user of nginx is www-data. I can verify this by "ps aux | grep nginx". But I still get 403 forbidden when trying to access index.html. Please help!!!