My PC has 2 HDDs. On HDD 1 Windows Vista is installed, and on HDD 2 openSUSE 11.1 is installed. I would like to install Fedora 10 on HDD 2 leaving untouched Windows Vista and use openSUSE's GRUB to switch between the two linux OS through the BIOS utility.

After resizing the HDD 2 with Gparted I was able to install Fedora 10, but it overwrote the GRUB of openSUSE 11.1. I posted a message on another linux forum, and someone suggested to use the rescue mode on openSUSE install DVD and to enter there the commands

chroot/mnt/sysimage
Grub install /dev/sd? ; (sd? being the place where openSUSE 11.1 Grub should be installed)

Sometimes you should also give the exit command after installing Grub
If everything goes well then you should have opensuse's Grub back
and we can later add Fedora to opensuse's boot loader.

However when I tried to do that the rescue mode required to login as root, and for some unknown reason it seemed not to recognize the root login being made.

The reason for resizing the HDD 2 was that openSUSE 11.1 was installed on the entire disk. I ran initially the installation media checks for openSUSE 11.1 and Fedora 10 DVDs and no errors were found. I will appreciate your feedback on how this matter can be solved: that is,

To install Fedora 10 on the same HDD that openSUSE 11.1 is and to perform the linux dual booting process using openSUSE's GRUB.

In order to give accurate instructions on what to do to restore Opensuse Grub, we will need to have your partition information or it will be just guessing. Boot Fedora, log in to a terminal and as root run the command "fdisk -l" (lower case letter L) and post the output.

You could use your Opensuse install CD, load it and open a terminal and if Opensuse is on sdb1, run the commands:

root (hd1,0)
setup (hd1)
quit

This assumes Opensuse on sdb1 and your second hard drive seen as hd1. I would suggest you post the fdisk -l output to verify this.

The Fedora 10 fdisk -l output is

Disk /dev/sda: 300.0 GB, 300090728448 bytes
255 heads, 63 sectors/track, 36483 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x69205244

Device...... Boot.....Start...........End...........Blocks..........Id.....System
/dev/sda1......................1.............262........2104483+.....82.....Linux swap / Solaris
/dev/sda2...*............263..........2873.....20972857+.....83.....Linux
/dev/sda3..............2874.......19476...133363597+....83.....Linux
/dev/sda4...........19477.......36483...136608727+.......5.....Extended
/dev/sda5...........19477........19502...........208813+.....83....Linux
/dev/sda6...........19503........36483...136399851.......8e....Linux LVM

I ran the openSolaris Live DVD but did not install it on HDD 2. I will appreciate your help in restoring openSUSE's Grub, and adding the required entry in the /boot/grub/menu.lst file to load Fedora 10.

Thanks once again for your kind assistance.

F10 /boot/grub/menu.lst output is in case it may help

# 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 (hd0,4)
# kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot=/dev/sda

default=1
timeout=5
splashimage=(hd0,4)/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.27.5-117.fc10.x86_64)
root (hd0,4)
kernel /vmlinuz-2.6.27.5-117.fc10.x86_64 ro root=UUID=8a750ce1-ff55-4bc3-bf6b-33f8fde8824f rhgb quiet
initrd /initrd-2.6.27.5-117.fc10.x86_64.img
title openSUSE
rootnoverify (hd0,0)
chainloader +1

The openSUSE option fails to load, and the following message appears onscreen:

Error 13: Invalid or unsupported executable format.
Press any key to continue...

You have 3 Linux partitions, sda2, sda3 and sda5 so Opensuse is on one of those and I will assume it is sda2. If not, make appropriate changes:

I'm assuming you are abl to boot into Fedora?? If so, change the menu.lst entry from the one you posted below for Opensuse to:

title openSUSE
rootnoverify (hd0,1)
chainloader +1

The entry you currently have is pointing to a swap partition which won't work. After this, you should be able to boot Opensuse. If you can do that, log into Opensuse and open a terminal/konsole and as root enter the following commands:

grub (here you should get a grub prompt: grub>)
enter following:
root (hd0,1)
setup (hd0)
quit

Hit enter key after each command. Re-boot. Also, I assume you do not have your windows drive attached. Do not attach until you have completed these steps and re-booted into Opensuse. My previous suggestion was made assuming you had both drives attached and your fdisk output indicates only one drive attached thus changing the numbering for Grub and Linux. With this set up, you will need to boot between drives with BIOS changes.