Personally I prefer grml.org's rescue cds.
First of all the most important is to get a cd that matches your $arch like i386/amd64.
- You boot the cd and assemble the raid/lvms.
- mount only the root fs
- chroot into the root fs
- outside the rootfs stop udevd
- inside the rootfs start udevd
- assemble/scan/mount the missing filesystems inside the chroot (the most important is the usr and boot)
- rebuild the initramfs
- on debian (i think it is the same on ubuntu) run:
- update-initramfs -uv -k $yourkernelversion
- update-grub or update-grub2
If something else is wrong like lvm2 uninstalled by accident or something like that you can reinstall it in the chroot. If you give the exact error message we try to take a look.
Solution is to use a bios_grub partition, which is not the same as the /boot partition.
By default the bios_grub partition is 1MiB, and it must be flagged bios_grub. Mine is the first partition on my disk. If your partition 2 is actually /boot as parted suggests, that would not be correct and you should make another 1MiB partition.
With GPT and GRUB2 the minimum filesystem has three partitions: bios_grub, root, swap. (not perfectly sure swap is required)
Why does grub fail to boot after simply running "grub-install"?
Unknown... You'd think it wouldn't modify anything if it says clearly it cannot embed so it can't work.
Why does it say "file not found"?
/vmlinuz is a symlink that uses the boot partition, and the boot partition is corrupt. The bios_grub code was written on top of its ext3 structure. This probably meant that /boot was not mounted, and the grub files seen there were actually on the root system, which didn't contain the kernel.
Why doesn't grub want to install without this setting I set with parted
A GPT partition table has no space for a bootloader, unlike MBR. So a specific partition must be created to hold the boot code. Before running "grub-install", specify this partition with the command:
parted /dev/sda set 1 bios_grub on
I thought all I needed was a separate /boot. How does the Ubuntu CD installer install it without the bios_grub setting?
This requirement seems to be all that is needed for the Ubuntu installer, but it creates an unstandard system which is broken easily.
When GRUB says "This GPT partition label has no BIOS Boot Partition", it means the bios_grub partition, not /boot.
Best Answer
Have you tried this HOWTO? link
Also you might want to try this patch.