Grub2 Help

[dhess31]

I have a working Ubuntu install with the Grub2 bootloader. I need to manually add an entry to boot Fedora 13 off of sda.

Sda1 is the boot partition, sda2 is LVM.

None of the examples I've tried work, so any pointers would be helpful. I DO also have F13 grub installed on sda, but chainloading to it didn't do anything other than a blinking cursor.

TIA.

D

[weitjong]

Please see my post in this thread.
http://forums.fedoraforum.org/showth...97#post1364697

If your Fedora's bootloader is on Master Boot Record then use "set root=(hdX)" variant where X is the disk number where Fedora resides. If the bootloader is on the first sector of the boot partition then use "set root=(hdX,1)" variant.

[Don1500]

DHess,
I loaded Fedora 13 yesterday, I already had a working version of Ubuntu 10.04 running since release with no problems. After I loaded Fedora I booted into Ubuntu and, in terminal ran

sudo update-grub

when I rebooted there was Fedora, right on the bottom of the menu, where I wanted it. No problems.

Now I am triple booting with Ubunto 10.04, Windows XP, and Fedora 13. Everything works.

[dhess31]

Thanks for the help guys.

I had already tried "update-grub" and "os-prober" unber Ubuntu and neither of them worked.

I am actualy on a mac pro, and I think an odddity of the EFI Bios on this thing might be the problem.

My Fedora is on sda as mentioned earlier. I installed the fedora GRUB to the MBR of SDA.

The machine boots from SDB, which is Grub2 that Ubuntu put there.

I added this to the Grub2 "40" config file:

set root=(hd0)
chainloader +1

Then I ran update-grub. But when I select the Fedora entry it just reloads the original grub2 bootloader which isn't right. It's like the BIOS actually doesn't see sda as hd0.

So experimenting I changed the hd0 to hd1, which just gave me a forever blinking cursor. Changing it to hd2 boots Windows 7.

But now it gets even stranger. I was editing the grub2 entry for Fedora manually on bootup (by hitting 'e') but again none fo the options worked. I changed it BACK to hd1 hit control-c for the command line, and when I exited out of the command line...

Fedora booted.

So I'm thoroughly stumped lol.

D.

[weitjong]

From your explanation, I would give '(hd1)' another try. Don't forget to run 'sudo update-grub' after finished editing. Also you may want to explore other option as well beside chainloader. The fact I am doing because my main OS is Fedora and I want to boot into Ubuntu once in a while via chainloader. If your main OS is Ubuntu/Mint with Grub2 which is more powerful, you can also configure Grub2 to autodetect other OSes via the os-prober as pointed by Don1500. However, for this os-prober to detect Fedora, your system need LVM2 package to be installed and the LVM to be preloaded by Grub2.

To install LVM2, use the Software Manager or synaptic or apt-get as usual. The package name is lvm2.

To preload the lvm module, edit /etc/default/grub to add this line to the end of the file:

GRUB_PRELOAD_MODULES="lvm"

Reboot. The next time you run os-prober it should list other OSes on LVM (including Fedora).
Finally run "sudo update-grub" to add those new automatic entries into grub.cfg.

If you do this, you do no need the chainloader custom entries in 40_custom anymore.

[dhess31]

weitjong,

Following you instructions above fixed the problem completely. Now, the "os-prober" and the "update-grub" finds the Fedora installations like they are supposed to!

Thanks for your help!

D.