[clug] Overriding the BIOS' impression of a disk

Peter Barker pbarker at barker.dropbear.id.au
Wed Oct 29 08:48:12 EST 2003

On 28 Oct 2003, Darren Freeman wrote:

> On Tue, 2003-10-28 at 18:12, Martijn van Oosterhout wrote:
> > Umm, I solved it on one our motherboards by simply not telling the BIOS
> > about it. Linux saw it fine and went right ahead.
> I had similar experiences on a mobo with an 8GB limit.

I have a P-III motherboard which didn't enjoy an 80G disk. Reducing the
number of cylinders to a believable number (for the BIOS) allowed the
machine to boot. Naturally, linux ignores the BIOS settings and the full
capacity is available. This old trick is a good one, since it allows you
to /boot/ from the large disk (which if the bios was told "no disk", you
would not be able to do).

Interestingly, this trick would /not/ be possible on a couple of the
servers I was dealing with a week ago. Their bios had no facility for
specifying hte disk geometry. auto-detect or bust. You better believe that

> Darren

Peter Barker                          |   N    _--_|\ /---- Barham, Vic
Programmer,Sysadmin,Geek              | W + E /     /\
pbarker at barker.dropbear.id.au         |   S   \_,--?_*<-- Canberra
You need a bigger hammer.             |             v    [35S, 149E]
"They'll need a whole new Orwellian pseudo-crime-name for that... I
 suggest "digital molestation of kittens". -  Jeremi (14640) from Slashdot

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