XP and Redhat linux 9 dual-boot issue

Hello people,

I am using a machine that was setup for dual-boot with Windows XP and Redhat linux 9 on separate hard disks. GRUB showed RH9 and Windows as entries.

The machine was booting fine until I attached another hard disk with Fedora Core 3 (FC) on it. I did a fresh installation of FC.
Now, when I start this machine without the FC hard disk, I get "GRUB hard disk error" message. With FC disk, the machine can load GRUB from FC and move on. It even shows an entry for Windows and I can boot Windows from there.

When I mount the RH9 disk under FC, I can see all the partitions and the /boot partition has a grub.conf. So all the data is there.

What is wrong here?
I dumped the MBR from RH9 disk and I see strings like "Invalid partition table". Should I re-install GRUB in MBR?

After Googling, it looks like "GRUB hard disk error" is from stage 1.

Thanks for any help.

When you did that install of FC3 did you let it install GRUB also? If so then there is your problem as GRUB needs the FC disk to fine the files it needs to boot. Between rh9 and FC i think they changed how they label the partition. Check that out.

It looks like HDs setup problem. Post the contents of RH9's grub.conf file and output of fdisk -l command. Post the contents of FC3 grub.conf file too.

Lazydog,
Yes, if I remember, I must have installed GRUB when I installed FC3. But isn't this on FC disk's MBR? I am wondering if that changed something in BIOS.

Casper,
Here hdg is FC3 and hdb is RH9.

Output of
> fdisk -l
Disk /dev/hda: 40.0 GB, 40020664320 bytes
240 heads, 63 sectors/track, 5169 cylinders
Units = cylinders of 15120 * 512 = 7741440 bytes

Device Boot Start End Blocks Id System
/dev/hda1 * 1 5169 39077608+ 7 HPFS/NTFS

Disk /dev/hdb: 6448 MB, 6448619520 bytes
240 heads, 63 sectors/track, 833 cylinders
Units = cylinders of 15120 * 512 = 7741440 bytes

Device Boot Start End Blocks Id System
/dev/hdb1 * 1 14 105808+ 83 Linux
/dev/hdb2 15 695 5148360 83 Linux
/dev/hdb3 696 833 1043280 82 Linux swap

Disk /dev/hdg: 10.0 GB, 10005037056 bytes
255 heads, 63 sectors/track, 1216 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/hdg1 * 1 13 104391 83 Linux
/dev/hdg2 14 1216 9663097+ 8e Linux LVM
----------------------------------------------------------------------------------

RH9's grub.conf -

default=0
timeout=10
splashimage=(hd1,0)/grub/splash.xpm.gz
title Red Hat Linux (2.4.20-8smp)
root (hd1,0)
kernel /vmlinuz-2.4.20-8smp ro root=LABEL=/
initrd /initrd-2.4.20-8smp.img
title Red Hat Linux-up (2.4.20-8)
root (hd1,0)
kernel /vmlinuz-2.4.20-8 ro root=LABEL=/
initrd /initrd-2.4.20-8.img
title Windows
rootnoverify (hd0,0)
chainloader +1
------------------------------------------------------------------
FC3's grub.conf -

default=0
timeout=5
splashimage=(hd2,0)/grub/splash.xpm.gz
hiddenmenu
title Fedora Core (2.6.17.7)
root (hd2,0)
kernel /vmlinuz-2.6.17.7 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.17.7.img
title Fedora Core (2.6.9-1.667smp)
root (hd2,0)
kernel /vmlinuz-2.6.9-1.667smp ro root=/dev/VolGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.9-1.667smp.img
title Fedora Core-up (2.6.9-1.667)
root (hd2,0)
kernel /vmlinuz-2.6.9-1.667 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
initrd /initrd-2.6.9-1.667.img
title Red Hat Linux (2.4.20-8smp)
root (hd1,0)
kernel /vmlinuz-2.4.20-8smp ro root=LABEL=/
initrd /initrd-2.4.20-8smp.img
title Other
rootnoverify (hd0,0)
chainloader +1
------------------------------------------------------------------------------
I have added entry for RH9 linux in FC's grub.conf.

Thanks.