[CentOS] CentOS 7 not installable using KVM-over-IP System

Hi, I just tried to install CentOS 7 using a Lantronix Spider KVM-over-IP System and its virtual media feature and to my surprise this did not work. The installation using the netinstall iso seems to work for a while (I see some dracut boot messages) but when the first stage of the boot is finished I get dropped into an emergency shell with the error message that "/dev/root does not exist".

I tried this on a Supermicro system and a gen-8 HP ProLiant Server both with the same result.

Using CentOS 6 instead worked fine and I could install the Systems without issues.

Any idea what the problem could be? Given that the iso is passed through as a USB storage device I'm not sure what the problem could be.

Regards, Dennis