raw disk copying?

[Tom Uban]

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...

My second attempt was with a NetBSD 3.0 install CD, exiting to
the shell and trying dd from rwd0a to rwd1a. I know that back
in the dark ages, this was possible, but apparently in these
modern times things have changed. When I try to do this I receive
a read only error on the /dev/rwd1a device. When the PC boots,
the wdX information goes by to quickly to read and the dmesg
command is not present on the install CD image.

Is what I want to do possible (anymore)? Do I have to resort
to purchasing Partition Magic or Ghost or something like that?
Do these programs even work on raw disks which have no file
system?

--tnx
--tom