GRUB error 18

[saurabh.sauron]

i tried to triple boot with fedora, ubuntu and windows. windows and fedora boot but ubuntu returns with GRUB error 18.
what is grub error 18 and how can it be corrected.
thnx

[eddie]

Give us the output of fdisk -l

Also tell us your Hard Disk setup. Which ports have you connected your Hard Drives to and which partition you have installed your OS on.

[saurabh.sauron]

it is showing command not found??? though i know it exists.

i have installed fedora on hdb1, ubuntu on hda6. my grub.conf file

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You do not have a /boot partition. This means that
# all kernel and initrd paths are relative to /, eg.
# root (hd1,0)
# kernel /boot/vmlinuz-version ro root=/dev/hdb1
# initrd /boot/initrd-version.img
#boot=/dev/hda
default=1
timeout=5
splashimage=(hd1,0)/boot/grub/splash.xpm.gz
hiddenmenu
title Fedora Core (2.6.15-1.2054_FC5)
root (hd1,0)
kernel /boot/vmlinuz-2.6.15-1.2054_FC5 ro root=LABEL=/1 rhgb quiet
initrd /boot/initrd-2.6.15-1.2054_FC5.img
title Microsoft XP Pro
rootnoverify (hd0,0)
chainloader +1
title Ubuntu
rootnoverify (hd0,5)
chainloader +1

[eddie]

it is showing command not found??? though i know it exists.You needed to use sudo. Anyways, your grub.conf shows the underlying problem. This is your problemtitle Ubuntu
rootnoverify (hd0,5)
chainloader +1
You can't load Ubuntu using chainloader because the root partition of your Ubuntu installation does not have any bootloader installed. chainloader is used for OS like Windows that always has bootloader like boot.ini available and chainloader can handle the booting process to these files.

You need to mention exact kernel and initrd image of Ubuntu partition in your grub.conf to boot it correctly. I am not a GRUB user thus I can't help you but some users like mehul or JGuru can help you here. They can give you exact syntax of what to mention in your grub file but chainloader will simply not work.

[mehulved]

You need to use su in FC to get access to fdisk. I guess it's the same for slacky?

[GNUrag]

go to your /boot directory and note down the exact filenames for vmlinux-2.6.-foobar and initrd.img-2.6-foobar
where foobar is some number rrepresenting your kernel version.

then put this for ubuntu:

title Ubuntu
root (hd0,5)
kernel /boot/vmlinuz-2.6-foobar root=/dev/hda6 ro quiet splash vga=791
initrd /boot/initrd.img-2.6-foobar
savedefault
boot

[saurabh.sauron]

thnx GNUrag. that solved my problem. it worked.