I'm using GRUB not LILO on my RH7.2 (2.4.7-10) and I want to repartition my IDE system disk. No other OS just RH on this disk, and no SCSI. I partitioned a new disk how I want it, then copied the system over. But now I can't get GRUB to come up - the console just hangs saying "GRUB". This is what I did:-

I took a new hd and put it in as hdb, then fdisk'd the desired partitions: hdb1 = '/' (type 83), hdb2 = swap (82), hdb3 = '/bkup' (83), hdb4 = Extended (5), and hdb5 = '/home' (83). '/boot' is in a separate partition on hda but I want it under '/' on the new disk. hdb1 lies well below cylinder 1024 and I made it bootable via fdisk.
Then I did the following:-
mke2fs -L / /dev/hdb1; mke2fs -L /bkup /dev/hdb3; mke2fs -L /home /dev/hdb5
mkswap -f /dev/hdb2
Mounted /dev/hdb at /mnt/hdb.
Created the mount points: /mnt/hdb/bkup and /mnt/hdb/home.
Mounted /dev/hdb3 on /mnt/hdb/bkup, and /dev/hdb5 on /mnt/hdb/home.
cd /; find . -depth -print0 | cpio -p0admV /mnt/hdb

Next I edited the copy of grub.conf on the new disk: /mnt/hdb/boot/grub/grub.conf. Because its no longer in its own partition I added the '/boot' prefix to grub/splash.xpm and the kernel path ie: 'splashimage=(hd0,0)/boot/grub/splash.xpm.gz', and 'kernel /boot/vmlinuz...'. Root is to be hda1 (when booting from the new disk) instead of hda2 on the original installation, so I changed this on the kernel line too.
Finally I edited /mnt/hdb/etc/fstab to remove the line for the '/boot' partition which doesn't exist on the new disk. Then I put the new disk in as the primary master and re...er hung with "GRUB" !

Any suggestions what might be up with GRUB?

This may point you in the right direction. I wrote a small script that makes a grub boot floppy this I used do make a bootable cd
here is the script:-

#!/bin/sh
#
echo makes a grub bootable floppy
#
# written on 1st May 2002
#
if [ -z $1 ] ;
then
echo " "
echo "needs kernel file as a parameter eg"
echo "make_grub_boot_floppy vmlinuz.w.x.y"
echo " "
exit
else
kernel="/boot/$1"
fi
echo " "
echo "Low level formatting floppy"
echo " "
fdformat /dev/fd0
if [ $? != 0 ]
then
echo "Faulty floppy disk or drive"
echo "Floppy failed to format properly"
exit
fi
exit
echo " "
echo "makeing ext2 file system"
echo " "
/sbin/mke2fs /dev/fd0
if [ $? != 0 ]
then
echo "Failed to make file system on the floppy"
exit
fi
#
mount /dev/fd0 /floppy
if [ $? != 0 ]
then
echo "Floppy could not be mounted"
exit
fi
echo " "
echo "Setting up /boot/grub and copying files"
echo " "
cd /floppy
mkdir boot
cd boot
echo " "
echo "copying kernel"
echo " "
echo " "
cp $kernel vmlinuz
mkdir grub
cd grub
cp /boot/grub/* .
cp /home/source/shell/grub.menu.floppy grub.conf
cd $HOME
echo " "
echo "Running grub in batch to set up mbr"
echo " "
umount /floppy
grub --batch <<EOT
root (fd0)
setup (fd0)
quit
EOT
#
echo "Done"
#

hope that is ok I had to paste in into this in a few chunks!

here is the grub.menu.floppy file:-

#
# This is copied to grub.conf when makeing boot floppies
#
# written 2nd May 2002
#
title hda1 (linux)
root (fd0)
kernel /boot/vmlinuz ro root=/dev/hda1
title hda2 (linux)
root (fd0)
kernel /boot/vmlinuz ro root=/dev/hda2
title cdrom
root (fd0)
kernel /boot/vmlinuz ro root=/dev/hdc init=/sbin/recover
title windows or dos partition 1
rootnoverify (hd0,0)
chainloader +1
title windows or dos partition 2
rootnoverify (hd0,1)
chainloader +1
title floppy ... hit enter after invalid system disk
# note floppy is set to fd1 because on cd boot
# fd0 is used by the boot image
rootnoverify (fd1)
chainloader +1

I hope this helps. I use it to boot a linux system on a cd
largely copied from a redhat. It should anyway give you some pointers with luck.

The main bit I hadn't done was setting up the MBR for GRUB.

I'm still not quite there yet but I'm further down the road.

Thanks
Mike.