I tried a lot of things yesterday, and the situation today is that the HDD doesn't work anymore. Niether in the nas , or the laptop. It makes the sound what laptops make when you connect a HDD via usb, but it doesn't show it anymore. Even in storagemanagemant, it only marks device doesn't work code 10. So , i think the HDD either died trying to use him in the nas, or the problem was their before. I will get me another HDD in the afternoone and hope that one will survive the action. Otherwise, they will ge an unplessant mail at Zyxel
Just in case your next Seagate drive does not work I have 2* 3tb WD red drives in a NSA325 in raid 1 working fine.