Installing a NetBSD DomU on a file-backed disk

[Blair Sadewitz <blair.sadewitz%gmail.com@localhost>]

Hello,

I have a hosting service which provides a single file-backed (I think
they're using LVM) disk image for its DomUs.  Under linux, the only
disk device I have is /dev/xvda1.  On NetBSD, I get xbd0.  Obviously,
a conventional installation here fails.  They're using pv-grub, and
I'd know what to do if I had an actual _raw_ disk device that I could
label, but I don't.  I've looked at people's experiences and
instructions for prmgr.com, linode, Amazon EC2, etc., etc., and all of
those services bestow upon the user the hallowed privilege of one or
more _actual_ virtual disk devices! ;-)

Is there a way I could get NetBSD working here?  Is there something
I'm possibly doing wrong that I need to do right?  Do I not understand
what's going on?  Does pv-grub actually do anything inside the DomU?
That is, are any of the files in /boot/grub actually needed besides
/boot/grub/menu.lst (grub.conf)?  Please do clue me in.

Thanks,

--Blair