Shoutbox

Under Linux, USB devices are mounted as SCSI devices, so you'll need to add a mapping from /dev/sda0 to wherever you wish to mount the external HDD e.g. /mnt/external, obviously with the flags needed to tell Linux the filesystem.

Example:
/dev/sda0 /mnt/external vfat auto,users,exec

You can also use noexec to not run stuff, and noauto to not mount on boot.

I used to run Linux, and had (still have) an external HDD. Can't remember if Fedora set it up for me, or if I did it manually: I just know what I saw in my fstab.