I have a bit of an unusual problem. I've installed lubuntu 12.10 AMD64 on my system, placing / and /boot on an SSD and the rest on a hard disk. Everything except /boot is encrypted. All was well until the SSD started producing I/O errors. It appears I'm going to have to return it for replacement, which means being without it for a few weeks.
As a substitute I copied everything from / and /boot onto an SD card, installed grub on it (
grub-install /dev/sdf), and figured I could use the SD card as my boot disk until the replacement SSD arrives. However, Grub doesn't seem to agree - once the SSD is disconnected and the system powered on again, Grub boots from the SD card, but only says:
error: no such device: 5ab2e581-some-guid. grub rescue>
I don't recognize that GUID it's complaining about - it's not in grub.cfg, grubenv, or any other text files I found in /boot, and
sudo blkid doesn't show it.
Piecing together what information I could find about this prompt I came up with the following set of commands that seemed like they should be able to boot the kernel manually from here:
set root=(hd0,msdos1)/boot set prefix=(hd0,msdos1)/boot/grub insmod linux linux (hd0,msdos1)/boot/vmlinuz-3.5.0-26-generic root=/dev/sde1 rootdelay=5 boot
but the kernel doesn't seem to notice the SD card, and fails saying I need to provide an appropriate
root= parameter and giving a list of available partitions - except the list is empty.
If, on the other hand, I do:
set root=(hd0,msdos1)/boot set prefix=(hd0,msdos1)/boot/grub insmod linux linux (hd0,msdos1)/boot/vmlinuz-3.5.0-26-generic initrd (hd0,msdos1)/boot/initrd.img-3.5.0-26-generic boot
it boots into an initrd image where I can see my SD card (on /dev/sde1, not /dev/sdf1, which is where I got sde1 in the above commands), but it doesn't appear there's any way to boot it from here either.
I don't know what I've missed here - what is this unknown GUID grub is looking for, and why isn't it able to find and boot the kernel on the SD card?