Date: Wed, 12 Apr 1995 12:30:34 -0700 (PDT) From: Poul-Henning Kamp <phk@ref.tfs.com> To: bde@zeta.org.au (Bruce Evans) Cc: ache@freefall.cdrom.com, CVS-commiters@freefall.cdrom.com, ache@astral.msk.su, cvs-sys@freefall.cdrom.com, dufault@hda.com, julian@tfs.com Subject: Re: cvs commit: src/sys/scsi scsi_base.c Message-ID: <199504121930.MAA09852@ref.tfs.com> In-Reply-To: <199504121922.FAA23975@godzilla.zeta.org.au> from "Bruce Evans" at Apr 13, 95 05:22:48 am
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> (1) I oversimplified. It isn't useful if it differs from the BIOS > geometry. E.g., ESDI drives sometimes say that they have 2 more > cylinders than they have, and ESDI and IDE drives may be configured > with a different geometry than the one claimed by the drive if the > BIOS supports this. I think those +2 is our fault... > (2) I oversimplified. It isn't bogus if it is the same as the > physical geometry; there are various levels of bogusness depending > on how well translations are hidden from the software. But it comes out to the size of the disk after all... > (3) I oversimplified. It's useful if the BIOS geometry is unknown > or wrong. E.g., for my 4.3G drive, the BIOS geometry may be is > C=1023/H=64/S=32, which loses over 3/4 of the drive, while the > geometry printed by the recently restored printf is > "(8410200 S), 4076 C 20 H 103 S/T". The problem will be worse for > drives larger than 8GB. I consider ""(8410200 S)" size, which is useful, and "4076 C 20 H 103 S/T" geometry which is bogus... > (4) I oversimplified. The number of sectors/track is usually an > average... -- Poul-Henning Kamp <phk@login.dknet.dk> -- TRW Financial Systems, Inc. 'All relevant people are pertinent' && 'All rude people are impertinent' => 'no rude people are relevant'
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