Thought I would follow up just in case anybody ever needs this information...
It goes something like this:
sata drive was hd0 to the grub boot loader, as soon as I added the ide drive the sata drive got bumped to hd1 and the ide drive became hd0. grub has a number of 'boot' stages (there is info out there that better explains this so I'll leave it to the grub masters!). Basically stage 1 is written to the master boot record (mbr). Since the mbr is rather small it can't hold all the required code for grub so more code has to be read from another place (this is known as stage2). When grub starts you see something like:
Loading grub stage2...
This is the mbr stage1 loading the code in stage2. Now the mbr has a pointer for where to find stage2. It is something like (hd0,1)/boot/grub/stage2
Which translates to something like /dev/sda2/boot/grub/stage2
However as soon as I added the ide drive this ended up looking at /dev/hda2 which happens to be my cdrom! and so stage2 can't be found and grub just sits there doing nothing! (GRUB...)
I fixed this by doing the following:
Insert a blank floppy.
cd /boot/grub (this may be different on other platforms)
dd if=stage1 of=/dev/fd0 bs=512 count=1
dd if=stage2 of=/dev/fd0 bs=512 seek=1
copies stage1 and stage2 to a floppy disk.
reboot the computer with the floppy disk inserted, you may need to change the boot order in your bios so that the computer boots from the floppy before the hard drive or cdrom.
You will see something like:
grub>
This is the grub command shell:
now for my system I typed (all one line):
install (hd1,1)/boot/grub/stage1 d (hd0) (hd1,1)/boot/grub/stage2 p (hd1,1)/boot/grub/grub.conf
This does the following:
install is a grub command to tell grub to install the stage1 from (hd1,1)/boot/grub/stage1 to (hd0) the d option is used to tell grub that it's a different disk
(hd1,1)/boot/grub/stage2 tells grub where to find stage2
p (hd1,1)/boot/grub/grub.conf tells grub where to find the configuration file - again more details can be found on the web...
As soon as I fixed the mbr I was up and running again. A quick fix to the /etc/fstab file and my disk is visible again...
Hope this helps some poor unsuspecting soul :-)
The website that helped me most was:
http://www.linuxgazette.com/issue64/kohli.html
Thanks and acknowledgement go to Jaswinder Singh Kohli
Hube
P.s, don't forget that grub.conf will also need modifying as it references (hd0,0) etc.