Grub confusion

[Rashkae]

On 13-12-11 01:32 AM, Kevin O'Gorman wrote:
>
> All drives are MBR formatted.
>
> I described the situation poorly, reflecting the fact that I'm both
> frustrated and confused.  The 4 drives are the same make and model, so
> the BIOS can't tell me which one is which.  The mobo has 6 internal
> SATA-3 connectors, in a group of 2 and another group of 4, with no
> obvious order.  When I run update-grub, then boot, the grub bootloader
> has a peculiar idea of what kernels there are, that does not entirely
> agree with what's in /boot.  I can boot, but I have to choose the
> kernel carefully.
>
> This is surely partly a result of the fact that some of those other
> disks still have a Linux image of some kind, almost surely including a
> viable grub boot loader, and some of this shows in the options when
> booting.
>
> So I'm not sure what drive the boot loader is on.  I'm not sure what
> /boot it's using, so I'm not sure which /boot/grub/menu.cfg it's
> using.
>
> I want to simplify the situation, at least a bit.  But I do not want
> to lose those other Linux boot options, although I can do without
> their bootloaders and config files -- if only I knew which was which.
>
> Since I don't know exactly what's happening, I'm leery of destroying
> stuff for fear the system won't boot.  I'm pretty sure that the drive
> that became /dev/sda is the one the BIOS booted from, but I suspect
> that its notion of /boot is different from mine, and it's not being
> updated by update-grub.
>
> Waiting for clarity and inspiration........
>

Try unplugging all drives from your Mobo other than your boot drive.  
The BIOS should choose that one as the default boot device and boot, (or 
try to boot, as far as it gets until the missing partitions on other 
drives causes problems.  Most BIOSes remember and maintain the SATA boot 
device, even if you re-add the other hard drives.