using dd to backup entire hard drive

You can always use have dd output to standard out and pipe that through
ssh to another machine. Save it as an image or write directly to the
drive. Or maybe NFS.

I have always wanted to do this to image drives but I have been worried
about how it would handle a lot of empty space. I don't want to have a
20GB partition that only actually has 4GB worth of stuff on it and then
dd it to a gzipped image and have it take up 12GB. So I have typically
used ghost in the past. I suppose if I cleared out all the empty space.
Someone gave me an idea on how to do that but I can't think of it
right now.


Austin