If you have a same size additional partition in your box you can easily create an exact copy of the source partition. You will need to start in rescue mode 1st to perform the action below.
command:
dd if=/dev/hdaX1 of=/dev/hdaX2 bs=8192
X1 = source partition
X2 = target partition
After which you will need to change the GRUB and the FSTAB to reflect the changes
a) Grub needs a ned entry for the new partition
b) FSTAB needs a change from the X1 drive to the X2 drive
The Priest (with major thanks to Anders Johansson)
