[lfs-support] Grub 2.0 problem

Bruce Dubbs bruce.dubbs at gmail.com
Tue Nov 13 11:26:31 PST 2012

Tobias Gasser wrote:
> Am 13.11.2012 18:08, schrieb Bruce Dubbs:
>> Tobias Gasser wrote:
>>> Am 13.11.2012 03:20, schrieb Bruce Dubbs:
>>> what i missed in my original message:
>>> /sda1 is ext2
>>> /sda2 and /sda3 are ext3 (first attempt was with ext4, but as grub
>>> didn't work i made backups, reformatted with ext3 and restored).
>> insmod ext2 is supposed to be able to handle ext2/3/4.
> i have "insmod ext2" in my grub conf:
> ** cut
> set root='(hd0,1)'
> set timeout=10
> insmod ext2
> menuentry "linux 32bit" {
>      linux /boot/kernel-3.4.18-t32 root=/dev/sda2
> }
> menuentry "linux 64bit" {
>      linux /boot/kernel-3.4.18-t64 root=/dev/sda3
> }
> ** cut
> but as grub does not see the disk at all, neither grub.cfg is processed
> nor the ext2-module is loaded.
>> What symlink?  I don't know if grub understands symlinks, especially
>> from one filesystem to another.
> works fine. ubuntus grub has no problems. the 'old' grub 199 had no
> problems with it too. and it's not to another filesystem, it's simply to
> have /boot/grub available on the boot-partition:
> from within /mnt/boot after "mount /dev/sda3 /mnt" and "mount /dev/sda1
> /mnt/boot") i do "ln -sf . boot"
>> I agree that there is a problem between the BIOS and GRUB.  When you
>> install the ubuntu system, what are the contents of grub.cfg.  Also what
>> is the output of 'mount'.
> once again: i did NOT install ubuntu. i just use the ubuntu life-cd to
> boot into the live environment. i don't install. i just open a terminal,
> mount my /dev/sda3 to /mnt and /dev/sda1 to /mnt/boot and do
> 'install-grub --boot-directory=/mnt/boot /dev/sda'
> thus i have nothing of ubuntu except the boot-loader. not even the
> grub-xx tools are from ubuntu, they remain my own compiled binaries. NOW
> the system can boot, but as soon as i reinstall grub with 'install-grub
> /dev/sda' after booting, my compiled LFS-version of grub fails to see
> any disk.

OK, so I now understand that both sda2 and sda3 are lfs systems.

What I suggest doing is

mount -v /dev/sda1    $LFS/boot
mount -v --bind /dev  $LFS/dev

before going into chroot (either 32-boot or 64-bit system)

It would probably be best to also mount /sys, /proc, /dev/pts, and 
/dev/shm as in Section 6.2.

Then run 'grub-install /dev/sda'

Make sure the kernel is in /boot and /boot/grub has grub.cfg and the 
i386-pc directory with the modules.

Then exit chroot, umount the file systems and reboot.

GRUB should see your disk.

   -- Bruce

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