Make an exact duplicate of a NTFS filesystem partition under Linux
First make sure you have created /dev/hdb1 using Linux fdisk program. /dev/hdb1 partitions must be the exact same size of /dev/hda1 so that you create a direct raw copy of source.
Use fdisk -l command to view current /dev/hda1 partition size (cylinders).
# fdisk -l
Now use dd command as follows:
# dd if=/dev/hda1 of=/dev/hdb1