From owner-cvs-sys Wed Apr 12 12:50:06 1995 Return-Path: cvs-sys-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id MAA21746 for cvs-sys-outgoing; Wed, 12 Apr 1995 12:50:06 -0700 Received: from gndrsh.aac.dev.com (gndrsh.aac.dev.com [198.145.92.241]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id MAA21732 ; Wed, 12 Apr 1995 12:49:58 -0700 Received: (from rgrimes@localhost) by gndrsh.aac.dev.com (8.6.8/8.6.6) id MAA07668; Wed, 12 Apr 1995 12:47:32 -0700 From: "Rodney W. Grimes" Message-Id: <199504121947.MAA07668@gndrsh.aac.dev.com> Subject: Re: cvs commit: src/sys/scsi scsi_base.c To: phk@ref.tfs.com (Poul-Henning Kamp) Date: Wed, 12 Apr 1995 12:47:32 -0700 (PDT) Cc: bde@zeta.org.au, ache@freefall.cdrom.com, CVS-commiters@freefall.cdrom.com, ache@astral.msk.su, cvs-sys@freefall.cdrom.com, dufault@hda.com, julian@tfs.com In-Reply-To: <199504121930.MAA09852@ref.tfs.com> from "Poul-Henning Kamp" at Apr 12, 95 12:30:34 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Content-Length: 1782 Sender: cvs-sys-owner@freebsd.org Precedence: bulk > > > (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... IT IS NOT BOGUS!!! The only number in there that is slightly wrong is S/T, as it is really AVERAGE S/T. The number of cyclinders and heads are EXACT NUMBERS! I wish people would stop calling this whole line bogus, just because 1 number in it is not properly labeled. > > (4) I oversimplified. The number of sectors/track is usually an > > average... > > -- > Poul-Henning Kamp -- TRW Financial Systems, Inc. > 'All relevant people are pertinent' && 'All rude people are impertinent' > => 'no rude people are relevant' > -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation Company Custom computers for FreeBSD