Date: Mon, 24 Jul 2000 12:09:21 -0700 (MST) From: "Chad R. Larson" <chad@DCFinc.com> To: jhb@pike.osd.bsdi.com (John Baldwin) Cc: hausen@punkt.de, stable@FreeBSD.ORG Subject: Re: No /boot/loader (dangerously dedicated) Message-ID: <200007241909.MAA14568@freeway.dcfinc.com> In-Reply-To: <200007232030.NAA23028@pike.osd.bsdi.com> from John Baldwin at "Jul 23, 0 01:30:05 pm"
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As I recall, John Baldwin wrote: >> Folks, gemoetries are for brain damaged PC operating systems. >> All the box needs to boot is a proper MBR. BIOSes that >> don't boot from a dedicated disk are _broken_. > > No, they are actually smart in that they attempt to use a geometry > that matches the MBR so that you can move disks around. As a result, > when we try to fake it, it confuses them. No, they are for brain-damaged operating systems that are trying to stay compatable with drives built in the Jurassic era when geometry meant something. You and I both know that my Quantum Fireball doesn't have 63 heads, which would imply 32 platters. And never mind that there are a variable number of sectors on a track, depending on if we're talking an outer track or an inner track. Disks should be treated as a linear list of blocks. The rest is just overhead, chicken-waving, backward-compatability magic. The confusion results when two different O/Ss (or the device drivers, or the drive firmware) apply different mapping algorithms to turn a logical block address into a cyl/trk/sec value. What you're saying is that we should follow the existing convention of using values stored in the MBR because it will work with very old hardware, and you could move a drive from a new machine to an old one without leaving the data apparently scrambled. What some of us are saying is we don't care about moving drives around, or legacy hardware. And we know enough to recognize when that can be a problem, and are willing to deal with it. -crl -- Chad R. Larson (CRL15) 602-953-1392 Brother, can you paradigm? chad@dcfinc.com chad@larsons.org larson1@home.net DCF, Inc. - 14623 North 49th Place, Scottsdale, Arizona 85254-2207 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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