Configuring GURB after Fedora 12 dual boot

[Elssar]

I had Ubuntu 9.10 installed on my laptop. A while ago I dual installed Fedora 12 on the laptop & now I can't enter Ubuntu. I don't get an option to select the OS at start up, Fedora loads automatically. Can anyone help me configuring my GRUB?
This is my grub.conf file in fedora -
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,2)
# kernel /vmlinuz-version ro root=/dev/mapper/vg_elssar-lv_root
# initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=0
splashimage=(hd0,2)/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.31.5-127.fc12.i686.PAE)
root (hd0,2)
kernel /vmlinuz-2.6.31.5-127.fc12.i686.PAE ro root=/dev/mapper/vg_elssa$
initrd /initramfs-2.6.31.5-127.fc12.i686.PAE.img

Also, the Ubuntu installation is 64bit, whereas the Fedora installation is 32bit, don't think that should cause any problems, but I want to be sure.

[Herman]

You should be able to use your Ubuntu Live CD to reinstall your Ubuntu GRUB to MBR.

1) First boot your Ubuntu Live CD and open GParted and check to see if your Ubuntu partition has a file system label. The file system label makes it easier to work on, since it will be mounted under that name when you mount it. If it doens't already have a label, right-click on your partition and click 'Label', and give your Ubuntu file system a user friendly name.

2) Mount your Ubuntu file system by clicking on the icon for it in your 'Places' menu.

3) Use the command 'ls /media' to check the name of your Ubuntu file system's new mount point, will probably be named the same as your file system label from now on,

ls /media

4) Replace the word 'disk' in the command below with the name of the mount point for your Ubuntu file system you just verified in the above command and then run the command below,

sudo grub-setup -d /media/disk/boot/grub /dev/sda

Now you should have Ubuntu's GRUB restored to MBR in your first hard disk and you should be able to reboot, removing the Live CD and boot into Ubuntu.

[Herman]

If you an errors complaining about being unable to access a device.map file, try this command,

sudo grub-setup -d /media/disk/boot/grub -m /media/disk/boot/grub/device.map /dev/sda

Again, you must replace the word 'disk' in each instance with the real name of your mount point.

[Herman]

5) As soon as you have successfully booted into Ubuntu, you can run 'sudo grub-mkconfig -o /boot/grub/grub.cfg' to have Ubuntu scan your computer and update your GRUB menu with an entry for Fedora,

sudo grub-mkconfig -o /boot/grub/grub.cfg

[ajgreeny]

I was under the impression that F12 uses grub2, and if so you should be able to add ubuntu to the fedora grub menu simply by running

update-grub

in a fedora root terminal.

If that is successful but you still prefer to use ubuntu grub, boot into ubuntu and run

sudo grub-install /dev/sda

if you want grub on the MBR, which is easiest, or replace the sda with the disk or partition you want/prefer. Ubuntu's own grub will then take over from fedora's, and you can run

sudo update-grub

to get the fedora entry on your new grub menu.

[bodhi.zazen]

The version of Grub used in Fedora can not yet boot ext4. Since by default Fedora uses a /boot partition (for LVM) I guess they have not seen the need.

Install the version of grub from Ubuntu as outlined by ajgreeny (it will recognize Fedora).

[ajgreeny]

Oh crikey!

I forgot fedora uses LVM, which does make things more difficult, I think.

Do they do that just to baffle people? I remember the first time I tried installing fedora to a partition on a ubuntu machine and after restoring ubuntu's grub, could not get the fedora partition to mount with all the usual mount commands. It took a friendly soul from here to tell me that it would be easier to manually partition for fedora, without using LVM, and then be able to use the normal mount methods I was used to.

[Emmtor]

Hello everyone, I've had the same experience(although I used fedora 13).
I tried Herman's idea, but configuring grub didn't work. My Ubuntu partition is Labeled 'Ubuntu' and it sdb5.Anyway here's the output.

 $ sudo grub-setup -d /media/Ubuntu/boot/grub -m /media/Ubuntu/boot/grub/device.map /dev/sdb5
grub-setup: error: cannot stat /media/Ubuntu/boot/grub/boot.img

There is no such file as '/media/Ubuntu/boot/grub/boot.img'.
Is there supposed to be one?

Also my device.map is:
(hd0) /dev/sda
(hd1) /dev/sdb

Thanks in advance.

[Herman]

The grub-install command runs another command called grub-mkimage when GRUB is written to any hard disk's MBR. So yeah, there should be a boot.img in there especially if you have ever installed GRUB to any MBR, (as most of us would).

You may find it easiest in your situation to just chroot and run grub-install from inside your Ubuntu operating system that way instead, How to chroot.

[Emmtor]

Thanks for your quick reply. There seems to be another problem though..Sorry to be such a whiner, but I'm afraid there isn't a '/etc/resolv.conf' file either.

 
ubuntu@ubuntu:~$ sudo cp /etc/resolv.conf /media/Ubuntu/etc/resolv.conf
cp: cannot stat '/etc/resolv.conf': No such file or direcory

Searching resolv.conf led into these two files:
/usr/share/ubuntu-docs/ubuntu/sample/resolv.conf
/usr/share/man/man5/resolv.conf.5.gz
The first contained 5 lines:

search com
nameserver 204.11.126.131
nameserver 64.125.134.133
nameserver 64.125.134.132
nameserver 208.185.179.218


The second seems to be a manual of sorts, and gives general information about the resolver file, as well as other files.

Is there any way to create a resolv.conf file?
By the way, I have access to the Internet with the computer I am using. I read that if the modem provides the DNS it won't be necessary to copy and paste the resolv.conf file.
Are there any other options available?

It is not necessary to spoonfeed me, so if it's not easy to give me some commands, pointing to the right direction will work as well, I have no problem studying and reading documentation. Thanks to everyone!

Edit: I omitted the 'sudo cp /etc/resolv.conf...' step, but even after 'grub-install /dev/sdb'
there is still no boot.img file in '/media/Ubuntu/boot/grub'.