Xfs partition "move" ?

[Stefano Peluchetti <pelux@xxxxxxxxxxxxx>]

I need to "move" phisically the xfs root partition to the first block of my 
hd to ba able to enlarge it and cover all the available space.
As now the partition starts after 4GB i can' t engrow it to the full size of 
my hd (43GB) .
How could i do? 
Do i need a second HD?
Not a very good thing :)
Stefano