Boot loader problem after addiing SCSI disk

[Jack Challen]

Chiu, PCM (Peter) wrote:
> I have a nasty thought that the two 3ware 7500 cards are 64bit PCI cards
> so they have to sit where they are - only 2 64-bit slots on the
> motherboard.

Yikes. You may be looking at a bit of a problem.

You might be able to get grub loading successfully by messing with
controller order in your machine's BIOS such that the 3ware cards are
presented first. (Often called "Boot controller/device order" or
similar, but this is machine dependent).

If that doesn't work, you could probably get results by running
"grub-install /dev/sda" (i.e. the newly installed disk) -- you'll have
to change the grub info such that it then tries to load stage 2 etc from
sdb (i.e. the existing disk).
To clarify that paragraph:
You're installing the initial boot loader on the new disk, as that's the
one the BIOS expects to boot from, but you're telling the initial boot
loader to use the files (kernel etc) from your existing disk.

Once Grub's successfully loaded (and loaded the kernel), you'll quite
possibly find that your kernel throws away the BIOS-provided order
(which you've just specified) and re-discover the cards, and get you
back to the following order:

1) U160 card  -> New disk
2) 3ware card -> Existing disk
3) 3ware card -> Existing disk

Your fstab will currently probably be referencing /dev/sda etc, and
therefore mounting filesystems will fail. Here you'll be at the stage
that Emilio was talking about.

hth
jack
-- 
Jack Challen
Technical Consultant, OCSL.
http://www.ocsl.co.uk/