When you suceed don't forget to post your project schematic and S/W in the Gallery. What HDD ? What does that .mean ?
pranavtprakash: Arduino usb hostshield support hdd, android adk etc.... also using serial commands and soft programming arduino can support two usb serial ports at the same time and can be used to interface two usb hostshield then why do you reiterate that this project cant be done using arduino..????? .
It seems to me you are asking for advice and then not bothering to take account of it.
The answer is in Reply #15. And the same advice was in Reply #6
You are just wasting your time as well as ours.
DrAzzy: This is a project more fit for an RPi - in fact, I'm pretty sure it's trivial on an RPi....
OK, now we have the "X" out of the "XY problem".
The quickest and simplest way to do this is of course, to purchase the commercial device.
You can however, do it cheaper using a Raspberry Pi.
And yes, since the process does not require a large buffer, it could be performed by some sort of Arduino and shield(s - two of them), but using the Pi will be far easier to program (as all the code is already built-in), at least as easy to use, almost certainly faster and - get this - cheaper. There are many tutorials available on this very topic.