Howto record on an external HDD?

Hey,

I think, most of you are bored by my question, so I am sorry, but I really don’t get it.

I plugged an external HDD by USB to my Raspberry Pi 2 and want to use it for TV recordings. I am able to find it in the devices list, and I am able to choose the main directory of it as the recording directory in the dialog. But unfortunately – timer recordings are not made on the HDD, but on the internal flash memory, which is not big enough for that.

What can I do?

Greetings,

Joker