grub2 can't boot int oother installations / no such device error

[Oxygenic]

Hi,

I freshly installed F17 on a SSD (/dev/sda1) which worked fine.

Next I installed Ubuntu on /dev/sda3, my intention was to create a multiboot system. After rebooting grub failed with an error message "unknown filesystem". Using the F17 CD I could restore grub2 to boot into F17 again.

My problem: within F17 I created a new grub.conf by calling grub2-mkconfig. The second system (Ubuntu) was detected correctly, and a grub2-entry with the correct UUID of /dev/sda3 was added to grub.conf. But now when I try to boot into Ubuntu, after selecting the Ubuntu-menuentry, I get following error messages:

error: no such device <UUID of /dev/sda3>
error: unknown filesystem
error: you need to load the kernel first

What I tried next:

- I defined GRUB_DISABLE_LINUX_UUID=”true” in /etc/default/grub to avoid that grub2-mkconfig creates menuentries with UUID - but that did not change anything, the UUIDs are still used instead of device names.

- I checked the filesystem on /dev/sda3, it is correct and readable, so no reason fror grub2 to not to use it.

So how can I solve this? I'm really not happy with the way too complex syntax of grub2 configuration (which is impossible to be edited manually since that very often leads to a non-bootable system because grub2 stops using it without any error message). And I'm really not happy with the fact that grub2-mkconfig creates entries that do not work!

Thanks!

[george_toolan]

error: you need to load the kernel first

pebkas! Don't blame grub for your mistakes ;-)

When you installed Ubuntu you told it to overwrite the Fedora boot loader which is located in the MBR. You have to install the Ubunto boot loader in the Ubuntu partion /dev/sda3 instead.

[Oxygenic]

Originally Posted by george_toolan

pebkas!

Yes, pebkas, but on your side:

Using the F17 CD I could restore grub2 to boot into F17 again.

I'm already back on F17's bootloader and when using grub2-mkconfig in F17 I can see the changes made grub.conf - but they do not work.

So it is definitely a problem of grub2 (the one of my F1 installation on /dev/sda1).

[george_toolan]

This is not a Fedora problem at all. Please try a Ubuntu forum ;-)

I'm already back on F17's bootloader and when using grub2-mkconfig in F17

After you destroyed it with Ubuntu.

I can see the changes made grub.conf - but they do not work.

They cannot work, because you never installed the Ubuntu boot loader into the Ubuntu partition /dev/sda3.

So it is definitely a problem of grub2 (the one of my F1 installation on /dev/sda1).

No, it's not. Grub cannot boot an operation system which isn't bootable and that's what it keeps telling you:

error: you need to load the kernel first

[Oxygenic]

Originally Posted by george_toolan

They cannot work, because you never installed the Ubuntu boot loader into the Ubuntu partition /dev/sda3.

Shouldn't that be done by the Ubuntu-installer?

Nevertheless, now when I do a

grub2-install /dev/sda3

out of my Fedora-installation to have a bootloader on /dev/sda3 too, I get a message

/usr/sbin/grub2-bios-setup: warning: File system `ext2' doesn't support embedding.
/usr/sbin/grub2-bios-setup: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
/usr/sbin/grub2-bios-setup: error: will not proceed with blocklists.

And - you bet - it still does not work although there should be a bootloader on /dev/sda3 now. The previous installation was exactly the same except that grub 1 was used on both sides - so what is that basically different now?

[DBelton]

have you made sure you had the /boot partition for Ubuntu mounted when you ran grub2-mkconfig in Fedora?

If it's not mounted, grub2-mkconfig doesn't see it, so no menu entry will be created in your grub2 menu.

You don't need the grub2 bootloader installed in the Ubuntu partition unless you want chainload it and have a second grub2 menu appear when you select it from your Fedora grub2 menu. The Fedora grub2 will boot Ubuntu without chainloading it, though.

Mount your Ubuntu boot partition, then run grub2-mkconfig -o /boot/grub2/grub.cfg and it should see it and add it to your grub2 menu.

[Oxygenic]

That's exactly what I've done, all partitions have been mounted, grub2-mkconfig successfully detected them and wrote the related entries into grub.cfg (using the correc UUID of the drives).

After rebooting I could see the new entries (means I changed the correct grub.cfg) but it still isn't able to boot them.

[PiElle]

Originally Posted by Oxygenic

Nevertheless, now when I do a
grub2-install /dev/sda3
out of my Fedora-installation to have a bootloader on /dev/sda3 too, I get a message

/usr/sbin/grub2-bios-setup: warning: File system `ext2' doesn't support embedding.
/usr/sbin/grub2-bios-setup: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
/usr/sbin/grub2-bios-setup: error: will not proceed with blocklists.

try:
grub2-install --force /dev/sda3

[Oxygenic]

Different output in console but same result, other partitions/systems than the first one can't be booted with still the same error message...