Re: [gentoo-user] Having trouble installing grub on second disk

On Tue, 26 Jul 2005, Richard Fish wrote:

> michael@×××××××××××××.com wrote:
>
>> I test by rebooting and entering my bios settings, and then i set the
>> boot device to hd1 instead of hd0. Save and exit, and grub tells me
>> "Error 15: File not found".
>
> For grub, the (hd0) and (hd1) devices are the ordered in the same order that
> the BIOS puts them in, so if you are going to switch them around in the BIOS,
> you should set the entries in the grub.conf to (hd0,0) instead of (hd1,0).
> In otherwords, (hd0) is always "the disk currently being booted from".
>
> You can test this by editing the lines when grub comes up, and change kernel
> to be:
>
> kernel (hd0,0)/boot/vmlinuz root=/dev/hdb1
>
> -Richard

I'm glad to report that Richard's suggestion solved my problem. Thanks
very much!

After a bit of experimentation, this worked:

 	root (hd0,0)
 	kernel /boot/vmlinuz root=/dev/hdb1 init=/bin/sh

That's interesting, because the first line refers to the drive
(remember, it's my slave primary device, but in my BIOS I have it
selected for booting) as hd0, but the second line refers to it as hdb.
Yes, I tried hda, and it didn't work.

I did a bit of research after our initial email and it seems that grub
numbering starts with the BIOS boot device, and then goes up from there,
but I couldn't find any clear explanation of what happens with drives 
that preceeded the boot device. If you have 4 drives and you boot from 
the second, does grub go back and get the first at the end, or never? 
A topic for future research.

The information I found also suggests that this is somewhat BIOS
dependent, so future readers of this thread take note: this may not
apply to you. Trial and error may be the only foolproof solution.

Thanks again everyone,

Michael
-- 
gentoo-user@g.o mailing list