Bdtyktl

I recently re-installed my Mac OS X partition. This somehow messed up my entire partition scheme it seems.

First I got dropped to the Grub rescue> prompt when trying to boot Ubuntu. I had never having seen it before and help command was not recognized, so I started googling. I ended up reading most of the grub recovery documentation.

I made it boot by using the set command to set root and prefix variable, then loaded normal mode plugin and ran it. It Presented me with the normal grub boot menu, and I booted Ubuntu just fine.
As the documentation also states these changes are not permanent and I have to edit /boot/grub/grub.cfg - more specifically it states that I have to ensure variables search, linux and intrd variables.

My problem is with trying to edit this file, my Ubuntu installation fails to reboot. After some wait time, I shut it down the hard way. When I then try to boot again, i'm back at the grub rescue> prompt again...

So to make ubuntu boot I use these commands:

set prefix=(hd0,gpt6)/boot/grub

set root=(hd0,gpt6)

insmod normal

normal -> select ubuntu

When editing /boot/grub/grub.cfg the section I'm supposed to edit I edit like this (I think it's the search line making the screw up, but i cannot figure out what i may delete):

EDIT: REMOVED LINES TO MAKE THE EDITED LINES MORE READABLE!

Unedited entry :

set root='(hd0,gpt6)'

search --no-floppy --fs-uuid --set=root ebba50e2-d298-4764-afb5-463c47532158

linux   /boot/vmlinuz-3.2.0-23-generic root=UUID=ebba50e2-d298-4764-afb5-463c47532158 ro acpi_backlight=vendor acpi_osi=Linux  quiet splash pcie_aspm=force $vt_handoff

    initrd  /boot/initrd.img-3.2.0-23-generic

EDITED entry:

set root='(hd0,gpt6)'

search --no-floppy --fs-uuid --set=root ebba50e2-d298-4764-afb5-463c47532158

echo    'Loading Linux 3.0.0-14-generic ...'

linux   /boot/vmlinuz-3.0.0-14-generic root=/dev/sda6 ro acpi_backlight=vendor acpi_osi=Linux

echo    'Loading initial ramdisk ...'

initrd  /boot/initrd.img-3.0.0-14-generic

I think that I edited the last section in (the Ubuntu recovery menu entry) correctly. The first entry looks (Ubuntu normal mode) like the grub.cfg file itself wants it to look ? which is correct?
My question now is, is this change correct? - And will I have to do the same for every menu entry? ;)

NB. after this not working I tried sudo grub-install /dev/sda6 - but I get an error saying this is a partition, and embedding is not supported - this is noob info since I have not researched this part enough yet, just thought it might bring some useful information..

I had a similar problem, where I installed Ubuntu over Kubuntu. I finished installing and started my computer up, and BOOM, I no longer had a menu to choose my OS, only the rescue prompt. I started playing around, and I found out that the fix for me was simple:

I just needed to set a different hard drive to boot from. This probably won't apply if you're using only one hard drive. Somehow, when I installed Ubuntu, the bootloader either got moved or the BIOS got changed, but I had to set the boot order differently to see my menu again. After that, I can now see my grub menu.

Hope this helps!