raw disk copying?

I have a pair of IDE hard drives and I want to do a raw copy from one to the other. I've tried a couple of different approaches so far without much luck. My first experiment was with linux where I created a PC linux boot CD and hooked my two drives up planning to just dd from one drive's raw device to the other. To my amazement, I discovered that linux does not have a raw disk I/O capability by default. I tried using the block devices, but the resulting copy was not intact. After doing a bit of searching, I discovered that there is some sort of rawio extension which allows a raw device to be associated with a block device, but it also said that dd would not work with this raw device due to buffer alignment issues vs. DMA. Go figure...