[Fedora-xen] resizing Xen para-virtualized guest partition

[runmd]

I would like to know if it is possible to resizing Xen para-virtualized
guest partition.  For example,

I created a para-virtualized guest as 10GB.  Later down the road I would
like to grow it to 20GB.   Can I do this with it being just a file on Dom0.
The only possible solution I can think of is creating a new domU as 20GB and
then doing a dd command and copying one virutal disk to another.  But I
would like to just grow the guest, if possible.

Thanks
Terry