In answer to your question, I would suggest something more like:
dd if=/dev/hda of=/net/someremote/host.image bs=16384
that will get absolutely everything on /dev/hda as a single image,
not as a file. naturally you could then run gzip host.image if
you choose to. Now what's the bit about writing zeros? Is there
nothing on this disk? Do you _just_ want the MBR? If it's a DOS
partition MBR you want, you can do:
dd if=/dev/hda of=/tmp/MBR bs=446 count=1
That will copy your MBR to a file called /tmp/MBR which you can then
put back in place by using the same command reversing the of/if.
hope this helps...
---russ