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Date: Sat, 19 Oct 1996 00:18:13 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199610181418.AAA11364@godzilla.zeta.org.au>
To: freebsd-hackers@FreeBSD.org, j@uriah.heep.sax.de
Subject: Re: 2.2-961014-SNAP install problem
Cc: kuku@gilberto.physik.rwth-aachen.de
Sender: owner-hackers@FreeBSD.org
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>We've been repeating this over and over again: the only geometry you
>should use is the same as your disk is known to the BIOS.  If your
>disk is not used by the BIOS at all, you can pick whatever value you
>want, as long as the total number of blocks (C*H*S) on the medium is
>not higher than the medium capacity.  In this case, the ``dangerously
>dedicated'' mode is the only mode where you can use all the blocks of
>the medium

No,  `C' is not recorded anywhere (except possibly for MFM/ESDI/IDE
disks), there is no requirement that C*H*S <= the medium capacity,
and no advantage for the dangerously dedicated mode.

(which is normally larger than anything that could be
>expressed as a product C*H*S where all the elements are integer
>numbers).

No, medium sizes are normally smaller than 1024*255*63 (almost 8GB).
Most current controllers support C*255*63.  This geometry should be
used so that you don't have to worry about C > 1024 unless you have
a disk larger than 8GB.

Bruce