Booting problem

[Mark Haney]

Keith Powell wrote:

> Karl, Mark.
> 
> I have solved the problem.
> 
> Recapping, the XP drive is plugged and jumpered as the master and the 
> Ubuntu the slave.
> 
> If I have the master drive plugged in when installing Ubuntu, the 
> partitioner correctly recognises the slave as 'sdb'. However, if I have 
> the master unplugged, it calls the slave 'sda'. In my 'un-expert' 
> opinion, this is in conflict with what it should be.

Why should it be in conflict? In the mind of the kernel, the first drive 
is always assigned /dev/sda whether it was originally that or not.  (Or, 
back in the olden days /dev/hda).

It will only be recognized as such if the master is connected.  I know 
this sounds a bit counter-intuitive, but keep in mind the M/S jumper 
only affects drive designations if there is more than one drive.  If 
there is only one, the 'slave' designation doesn't apply.  Does that 
make sense?

Remember, the kernel will designate drives in the order they are seen. 
With just one drive, it's the first (and only).  With 2 drives, it falls 
back to asking which is Master, and tagging it /dev/sda.

> 
> So, I have installed Ubuntu with the master plugged in and it now works.
> 
> I expect, but am guessing here, that I could alternatively have 
> installed Ubuntu with the other drive unplugged and edited grub/menu.lst 
> to change sda to sdb.

Yeah that would probably have worked. I've done that in the past with no 
trouble.  But that's been ages ago.

> 
> There's just one thing which has happened, which I didn't want. Ubuntu 
> appears to have installed its grub onto the XP drive MBR. I want to find 
> out how to reinstall the XP MBR and change the Ubuntu one to the sdb drive.

You know, I'd recommend leaving it as is.  It's much easier to make grub 
see Windows than it is for XP to see grub.  (Or to pass the boot 
sequence on to grub is maybe a better phrasing).

Either way, whichever boot manager you load first will HAVE to know 
about both operating systems.  Otherwise the OTHER OS will never be 
'bootable' from there.

Make sense?
> 
> Thank you all for your help. I appreciate it.
> 
> Cheers
> 
> Keith
> 


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Mark Haney
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