[SOLVED] Grub 15 Error with redhat

[sonny99]

Hello All,
I am new to this forum and desperately need some help with fixing boot problem. I have installed redhat enterprise edition 5 on an external hard drive. I thought everything was installed fine until i tried to boot from that drive and got a Grub 15 Error. I read the earlier threads but was not able to solve this issue. I have an Ubuntu operating system which lets me edit the grub.conf file using vi.
I think this is the file that needs to be modified in order to fix this issue. If anyone has any idea as to getting around this problem, please help. I can post another response with the exact content of the grub.conf file. Thanks.

[devils casper]

Hi and Welcome !

GRUB has been installed in MBR of Internal disk but its config files are in External disk. Didn't you disable Internal disk in BIOS during RHEL installation?

Which disk is set as First Boot Device in BIOS? Which Operating System has been installed in Internal Hard disk?

First of all, re-install Boot Loader of OS installed in Internal Disk in its MBR.
Re-install GRUB of RHEL in MBR of External disk and edit grub.conf file.

[sonny99]

Thanks for the response , since i am new to this unix. i have tried to read many forums. Grub is installed on the external disk, althogh i am not sure how changing the internal boot loader of windows xp operating system would help. I did try to edit the grub.conf file, but i am not sure what to edit in it. Here is the copy of whats in that file: (if you think this might help to better undestand the problem). thanks again..

# 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 (hd1,0)
# kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu

title Red Hat Enterprise Linux Server (2.6.18-128.el5xen)
root (hd0,0)
kernel /xen.gz-2.6.18-128.el5
module /vmlinuz-2.6.18-128.el5xen ro root=/dev/VolGroup00/LogVol00 rhgb quiet
module /initrd-2.6.18-128.el5xen.img
title Other
rootnoverify (hd0,0)
chainloader +1

[devils casper]

Does Windows OS boot up fine on unplugging External Hard disk?
Post the output of fdisk -l command here.

fdisk -l

[yancek]

One of your entries in the grub.conf file is wrong:

itle Red Hat Enterprise Linux Server (2.6.18-128.el5xen)
root (hd0,0

The entry above shows Grub is looking for Red Hat on the first partition of the first drive. The entry 'root (hd0,0) indicates that.

title Other
rootnoverify (hd0,0)

The entry above for 'Other' would be windows and it also shows Grub looking for windows on the first partition of the first drive. Both systems can't be there.

If you have Grub installed to the root partition of the external and not its mbr, it won't boot. If you installed Grub to the mbr of the external with the correct entry and have the external set as first boot priority in your BIOS it should boot.

To get help on your specific problem, you will need to post the output of the command suggested by devils casper. It would also help if you could post the output of the commands: geometry (hd0) and geometry (hd1) from the grub prompt. It would be helpful to know if you can boot windows when external not plugged in.

[sonny99]

Thanks guys, I think i finally sovled it. Your inputs were very helpful.