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Date:      Sat, 11 May 1996 05:59:50 +0100
From:      "Gary Palmer" <gpalmer@FreeBSD.ORG>
To:        John-David Childs <jdc@ism.net>
Cc:        questions@FreeBSD.ORG, hardware@FreeBSD.ORG
Subject:   Re: disktab for Micropolis 4221-09/2112-15???? 
Message-ID:  <4885.831790790@palmer.demon.co.uk>
In-Reply-To: Your message of "Fri, 10 May 1996 22:57:38 MDT." <Pine.BSD/.3.91.960510225319.4776A-100000@optim.ism.net> 

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John-David Childs wrote in message ID
<Pine.BSD/.3.91.960510225319.4776A-100000@optim.ism.net>:
> Yes, I've been searching for these since 6pm.  Found an HPUX disktab for
> the 4221 (from the Micropolis web site), but FreeBSD 2.1.0-RELEASE boot
> disks (I'm doing a new install) chokes on the number of cyl/head/sec
> I entered.

> Micropolis docs are garbage (faxback), and the various hard disk reference 
> guides (including "TheRef" don't give enough info).  Any help appreciated 
> greatly.

The correct answer is to make a small DOS partition on the hard drive
so that FreeBSD can pick up the geometry presented to the computer by
the SCSI card. Most SCSI cards present a fake geometry to the PC to
get round limitations designed into the PC from the early days whem
people thought that 500Mb's would never ever be exceeded
(ha!). Without access to the BIOS from the kernel, FreeBSD doesn't
have any real way of finding this out, and a small DOS partition
(which can be deleted once the kernel is running and has read the MBR
to get the geometry) is the best way.

So the right answer is: it's not what geometry the drive has (which
for SCSI drives is often wrong anyhow as they have variable number of
sectors per track depending on the cylinder), but what geometry the
controller has for the drive ... The installer will choke on what you
tried as for multi-OS installations, you can't use the ``raw''
geometry but the one the BIOS sees.

Gary
--
Gary Palmer                                            FreeBSD Core Team Member
FreeBSD - Turning PC's into workstations. See http://www.FreeBSD.ORG/ for info.



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