Centos Xen resizing DomU partition and volume group

I have a setup like
so:

 Dom0 LV

            |

 DomU Physical Disk
 | |
 XVDA1
            XVDA2
 (/boot) (DomU PV)
 |
 VolGroup00
 (DomU
            VG)
 | |
 LogVol00 LogVol01
 (swap)
            (/)

I am
trying to resize the DomU root Filesystem. (VolGroup00-LogVol01) I realize that I now
need to resize the partition XVDA2, however when I try doing this with parted on Dom0 it
just tells me "Error: Could not detect file
system."

So to resize the root part
VolGroup-LogVol00 shouldn't the process
be:

# Shut down DomU
xm
            shutdown domU

#Resize Dom0 Logical
            volume

lvextend -L+2G /dev/volumes/domU-vol

#
            Parted 
parted /dev/volumes/domU-vol

# Resize root
            partition
resize 2 START END

(This is where I get an
            error) "Error: Could not detect file
            system."



# add the vm volume group to Dom0
            lvm
kpartx -a /dev/volumes/domU-vol

# resize the domU
            PV
pvresize /dev/mapper/domU-pl (as listed in
            pvdisplay)

# The domU volume group should automatically
            adjust
# resize the DomU lv
lvextend -L+2G
            /dev/VolGroup/LogVol00

And
then obviously increase the fs, remove the device from kpartx
etc

The problem is I dont know how to resize the
partition? How do I resize this partition so I can run pvresize on the
DomU?

Thanks