From odroid US
This page stores quick tips, less involved than a tutorial.
Remove Root File System from Image
Say you don't like waiting so long to write a whole SD-Card image because you will be using an external drive for the RFS
(Copied from the Forum)
dd if=your-image.img of=/dev/sdX bs=1M count=512 sync partprobe fdisk /dev/sdX d 2 w sync partprobe