>Cloning a partition

# dd if=/dev/sda1 of=/dev/sdb1 bs=64K conv=noerror,sync status=progress

>Cloning an entire hard disk

# dd if=/dev/sda of=/dev/sdb bs=64K conv=noerror,sync status=progress

>Create disk image

# dd if=/dev/sda conv=sync,noerror bs=64K | gzip -c  > /path/to/backup.img.gz
# dd if=/dev/sda conv=sync,noerror bs=64K | gzip -c | ssh user@local dd of=backup.img.gz

>Restore system

# gunzip -c /path/to/backup.img.gz | dd of=/dev/sda

>To save the MBR as mbr_file.img:

# dd if=/dev/sdX of=/path/to/mbr_file.img bs=512 count=1