View Full Version : [all variants] reconfigure grub after reinstall

October 31st, 2010, 10:51 PM
I've upgraded the hdd in my macbookpro 5,5 and after installing OSX and refit and copying the ubuntu to its partition with rsync and the live CD, I am now stuck with the problem that refit won't recognize my linux partition.
After reading some forums/wikis etc. I've understood that grub has to be on a partition with linux. However, I'm not able to install grub with

grub-install --root-directory=[UUID] /dev/sda,
because the MBR of the hdd is not found. According to Refit, there is a mbr and it looks like it's ok... Grub could be installed with blocklists (that's what it says in the error message), however I have no idea what that means and if that is what I want.

Do you have any ideas how I could install grub so that my linux partition is found by refit?

October 31st, 2010, 11:12 PM
from an Ubuntu liveCD, you reinstall Grub to your harddisk

grub-install /dev/sdX
change /dev/sdX it into the device you want

November 2nd, 2010, 12:19 AM
Thanks for the answer. However, things aren't that easy :(:

ubuntu@ubuntu:~$ sudo grub-install /dev/sda
/usr/sbin/grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?).

and btw, the code I've posted in my first post leads to

ubuntu@ubuntu:~$ sudo grub-install --root-directory=/media/[UUID] /dev/sda
/usr/sbin/grub-setup: warn: This GPT partition label has no BIOS Boot Partition; embedding won't be possible!.
/usr/sbin/grub-setup: warn: 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/grub-setup: error: if you really want blocklists, use --force.

[UUID]=UUID of the partition containing linux. The same message appears if the root-directory option points to the efi partition...

Any ideas?

November 2nd, 2010, 01:32 AM
You might try installing grub-efi-ia32 or grub-efi-ia64, depending on whether your EFI is 32- or 64-bit (probably the latter, but I'm not positive of that). This version of GRUB works within the EFI framework rather than relying on the BIOS emulation used by the grub-pc package. As such, it eliminates the need for a BIOS Boot Partition. This change will also enable you to convert the flaky and downright dangerous hybrid MBR (http://www.rodsbooks.com/gdisk/hybrid.html) into a conventional protective MBR, which is much safer. OTOH, few or no online tutorials describe how to do it this way. I've seen some suggestions that X may work only in non-accelerated framebuffer mode when booting in EFI mode. That's definitely not a problem on my Mac Mini 1,1, but it's possible it's a problem on systems with other graphics chipsets. (Mine's got an Intel chipset, the 950 IIRC.)

November 2nd, 2010, 09:27 AM
Thankyou very much for your help. On the page you linked to, it says that

Unfortunately, as of autumn 2010, rEFIt, or some tool associated with it, seems to produce misconfigured hybrid MBRs, requiring elimination of a duplicate 0xEE MBR partition.
...which might explain my problem. Anyway, I'm going to give grub-efi a shot tonight.