Turning a linux box into a storage appliance

[xyz]

Hi all,

After hours of Google searching I give up and ask...

I am trying to convert a desktop PC running linux into a storage appliance.

The idea is to fit the box with a bunch of disks, attached to a RAID card or
IDE cards and LVM and setup fault tolerance.

The box would be accessed from another computer as a Direct Attached Storage
(DAS) device, via the USB or IEEE-1394 port, just like an USB external
drive, but fault-tolerant.

There's quite some litterature available about how to convert a linux box
into a Network Attached Storage (NAS) using Samba.

But I can't find anything about how to access the box at the block level
stack, not the network stack, and present the Linux box to other computers
as a storage device, not host.

I suppose it's not as simple as doing a dd between /dev/usb and /dev/hda?

Any help appreciated.

Thanks.

Eric