How Do You Record To An External HDD On A VU+ Solo With VIX Firmware?

Hi All, Sorry if this may have been posted already by someone, I've recently upgraded to a VU+ Solo from an Galaxy Box and struggling to figure out how to record to my external HDD every time I add timer it doesn't record and says my HDD is full when its been formatted on my pc.

Do i need to format it in any particular way ie exfat as its been formatted in NTFS.

Or am i doing something wrong? Its got VIX firmware on the box.

Any help would be much appreciated/

Thanks