Hi everyone,
thanks for your reply's. And what I get out of it is that your basicly saying that I don't need a NAS for the purpose I thought I needed it for.
I just need to continue the way I did it (though I only had 2 copy's instead of 3, still I had one drive at home and one drive in my parents house) just need to sync more often.
Are there also Windows programs that can check the file status (corrupt or not) and get the healthy file from the second drive and copy it to the first drive?