Debian using USB stick on diskless machine

[Ross Boylan <rossboylan@stanfordalumni.org>]

I have a diskless machine and figured it would be quicker to get it
running off a USB thumb drive than PXE boot.  I'd appreciate any
suggestions or advice.

I stuck Debian live on the thumb drive but discovered changes I made
in that environment were not persistent.  Ran the installer on the
live CD and installed to the rest of the thumb drive.  However, grub
said it could not install to the drive (which, of course, was in use
by the installer system).

I tried chroot'ing into the new system from the live system.  But,
even after mounting /dev and others for the chroot, grub-install says
root@debian:/# grub-install /dev/sda
Installing for i386-pc platform.
grub-install: warning: Attempting to install GRUB to a disk with
multiple partition labels.  This is not supported yet..
grub-install: error: embedding is not possible, but this is required
for RAID and LVM install.

There might be two issues: one, accessing sda, and the second that I
am using one big filesystem on top of LVM; there  is no separate
partition outside of lvm for grub.  This was mostly an oversight,
though I had hoped that current grub could cope.

Because this was a live image the partition table is msdos.  Which is
maybe not so great for grub, which needs more room.  The live image is
about 1G and the thumb drive is 32G.

Thanks for any help.
Ross Boylan