Re: [Sheflug] boot weirdness

[Netsonic <netsonic [at] xxxxxxxxxxxxxxxx>]

On Tue, 13 Jan 2004 10:04:19 +0000 (GMT), Richard Balthazor wrote:
>
> I've a machine with an IDE primary master HDD (/dev/hda) (with Win
> XP), a primary slave (CD-R), and secondary master HDD (/dev/hdc)
> (with Redhat). The dual boot is managed by GRUB; the boot loader is
> installed on the MBR and the rest of it in /boot, as per default.
> All works well.
>
> I added a secondary slave HDD: set the jumper to 'slave', detected
> it in BIOS with auto-detect and then switched to User-defined
> whilst keeping the same settings, and plugged it in.  Now it
> reaches Grub and fails either with "GRUB Hard disk error" and Grub
> error 21 (ie, semi-randomly).  The secondary master HD definitely
> has the master/single drive jumper setting. The sec. slave HDD
> (which has a non-bootable filesystem on it) is recognised quite
> happily as /dev/hdd (as expected) if I boot from CD, as are all the
> other disks.  Running grub or grub-install manually from a CD boot
> also recognises all the disks in the correct order (hd0=pri.
> master, hd1=sec. master, hd2=sec. slave).   I'm getting a similar
> problem with LILO but I'm not as familiar with that.
>
> So, if I understand correctly, adding the secondary slave is
> confusing the boot loader on the MBR sufficiently that it "can't
> see" the stage 2 boot (which is on the sec. master) - either it
> suddenly can't see hdc, or it's managed to swap hdc and hdd and is
> looking in the non-existent /dev/hdd/boot, although booting from CD
> seems to deny this).
>
> The only really dumb thing I haven't tried is a) cable swap, or b)
> swapping the order of the drives on the cable, which I haven't
> tried through lack of cable.  Surely it can't be this?
>
> Any ideas greatly appreciated.
>
>
> cheers in advance,
> R.
>

First things I would look at (having being working on grub the last few days) is:

1. Is there anything in /etc/fstab that may be causing this ie. any reference to /dev/hdd that shouldnt be there?

2. Is there any kind of bootblock on the disk from before ie. did it previously have a bootable OS installed on it ?

3. If you have a look at the disk geometry when Redhat is loaded and see what is reported; does this match the geometry you entered in the BIOS ?

When I set my hard disks up in the bios, if I left it on auto and the bios screen filled with auto-detect rubbish that didnt need to be there. So what I did was to look at the values it entered in the bios setup screen and then entered those myself in the user-defined mode.

One other thing might be to have a look on the drive itself. Usually there is a manufacturers sticker on there with make & model no, geometry settings etc etc.

I believe some of the newer IDE cables DO expect the drives to be connected in order ie first drive in the first connector, second drive in the second connector (the one at the end). Not 100% sure on this though.

HTH.

Steve.

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