dd if=/dev/cdrom | ssh
2) copy the Linux MBR:
dd if=/dev/hda of=hda.mbr bs=512 count=1
3)Create compressed image of a drive :
dd if=/dev/hda1 bs=1M count=150 | gzip > hda1-image.gz
*you should know the size of the partition you're about to compress - use df -h for that.
also replace the "150" with the number of used megabytes on the partition.
4)Wipe a disk from Linux
dd bs=1048576 if=/dev/zero of=/dev/hda