Comment 43 for bug 430333

@Felix Zielcke: Thank you for the explanation. Maybe the bug is not with grub but maybe the Debian installer not specifying the right device, or something getting confused about which is the target device... ? I was finally able to get a small Debian installation working on an SD card using http://wiki.debian.org/DebianEeePC/HowTo/InstallOnSDcardOrUsbStick (but of course that is grub not grub2).

After Ubuntu's alternate installer (Debian Installer) failed I also tried to get grub2's update-grub to write its files using the procedure at http://www.ubuntu-inside.me/2009/06/howto-recover-grub2-after-windows.html -- The steps are: mount the target device (for me it was /dev/sdc), and then mount the booted system's /dev and /proc to the target directory, then chroot into the target directory and run grub-install /dev/sdc. From watching the LEDs it looked like grub wrote or read something from /dev/sdb (the booted USB stick) as well as /dev/sda (the SSD I was trying to leave alone).

It sounds like you're saying that even though I mounted the /dev and /proc and chroot-ed into the mounted target I still must explicitly specify the device for update-grub's root, so the command would be (?? haven't tested):

grub-install /dev/sdc --root-directory=/dev/sdc/