From: Bob Weaver <[EMAIL PROTECTED]>
Subject: Problems with SCSI drives and Grub
Date: Wed, 31 May 2000 16:00:35 -0600
> I hate to bother everyone with this but I have tried all I can think of
> and can't figure this one out. We've got a system with one IDE drive
> (linux sees it as hda and grub as hd0) and two scsi drives as follows:
>
> /dev/sda (hd1 to grub) 1111 cylinders windows 9.1 GB IBM Drive (BIOS set
> to boot to scsi and hits this drive first)
> /dev/sdb (hd2 to grub) 527 cylinders Linux (part 1) swap (part 2) 4.5 GB
> IBM Drive
You are wrong. When you set your boot drive to /dev/sda, the BIOS
exchanges the order of your drives. So now the order should be:
/dev/hda -> (hd1)
/dev/sda -> (hd0)
/dev/sdb -> (hd2)
I've already written a bit about that in the documentation:
> Note that GRUB does _not_ distinguish IDE from SCSI - it simply
> counts the drive numbers from zero, regardless of their type. Normally,
> any IDE drive number is less than any SCSI drive number, although that
> is not true if you change the boot sequence by swapping IDE and SCSI
> drives in your BIOS.
Because I'm just talking about what happens normally, you should check
if my suggestion is really correct, by running GRUB from a floppy.
There are some solutions for that. If you want to manage the
installation on GNU/Linux, you should use the "device map" feature to
tell the grub shell the correct drive mappings. See the documentation,
for more details. Another solution is to install GRUB in the native
environment instead of the grub shell. This is definitely a desirable
way whenever you can boot GRUB from a floppy. However, if your machine
has no floppy drive unfortunately, you may not choose this.
Cheers,
Okuji
