[CentOS] Resizing a Xen DomU disk image

Hello Mailing List!

A quick question.  Has anyone gotten a resize (in my case grown) a Xen
DomU disk image?

Here is the procedure I have followed:

1.  Install a DomU using virt-install
	Customize xvda to be all one partition ext3
2.  On Dom0:
	dd if=/dev/zero bs=1G count=1 >> <my_disk_image>
	ll -h (Image is now 1GB larger)
	xm create <DomU>
    On DomU:
	df -h (Size has not changed)
	shutdown -h now
    On Dom0:
	e2fsck -f <my_disk_image> (Errors Bad Magic...)
	resize2fs -f <my_disk_image> (Errors Bad Magic...)
	xm create <DomU>
    On DomU:
	df -h (Still reports old size)

I am assuming that because resize2fs didn't run that the DomU doesn't
know about the additional space.

Thanks in advance!