FERPA alternative for German universities
According to the German Datenschutzgesetz and several state laws, it is forbidden to use private cloud services for storage of personal data. If you are at a university with access to ZENDAS, you can get a review of dropdox here.

A local server is fine, as long as you contact your local "Datenschutzbeauftragten" and announce the service. (S)he might have a form to fill in to evaluate the data security issues resulting from your installation. 

Tehre is no specific rule for universities, but the general rules from the German Datenschutzgesetz apply for universities as well. 

Platforms like moodle might breake existing German laws, it depends on the configuration of such systems (especially the tracing of activities is a problem).