From: "Christopher G. Stach II", Wednesday, February 24, 2010 12:45 PM
... I meant from the perspective of Linux. It is unclear to me how many layers are involved and whether or not you already did the kpartx bit, but if in case you didn't... If Windows is using the LV as an entire disk and partitions it, you have to use that partition table, too. ...
If Ben did, what I think is, a standard install, he created a LV and gave it to virt-install with the CD for install. Windows would treat that LV as a disk and create a partition table and then create an NTFS filesystem inside that new partition. (from your responses, Chris, I'm guessing you know this. I'm just prefacing my guesses to put my suggestions in context.)
In order to access the NTFS partition, you have to get Linux to read the partition table from the LV and create new devices. (I'm guessing you know this too, Chris, from your responses, but I think Ben might not be understanding what really is going on).
Recently, I was required to expand a virtual drive/NTFS for a virtual Windows XP machine. I documented my process, which includes using kpartx to create a new device so the ntfs tools can see the nested partitions, at http://wiki.centos.org/EdHeron/DomU_LVM_NTFS_resize. After posting it in the doc list, a simpler suggestion was made that I have yet to test. However, there are pieces there that might help Ben understand what is going on.
Ben, if this doc helps, let me know. Since it explains a little about virtual machine nested filesystems and how to access them, I may change it with that in mind.