Date: Thu, 21 Mar 1996 10:56:08 +0100 (MET) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-hackers@freebsd.org (FreeBSD hackers) Cc: dave@kachina.jetcafe.org (Dave Hayes) Subject: Re: Adding a damn 2nd disk Message-ID: <199603210956.KAA12368@uriah.heep.sax.de> In-Reply-To: <199603202044.MAA05712@kachina.jetcafe.org> from "Dave Hayes" at Mar 20, 96 12:44:16 pm
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As Dave Hayes wrote: > >One look in /etc/disktab shows you what to do next, or not :-> > > But sysinstall doesn't *use* disktab... Right. It doesn't. > >If you don't get the geometry of your SCSI disk, then please > >compile your kernel with the option 'SCSI_REPORT_GEOMETRY' > > Hmm. Why isn't the default kernel configured to do this? > I knew not about this option, which makes sense. Andreas was wrong here. Fdisk needs the geometry the BIOS is using -- not the geometry the disk claims to be. (The latter is largely irrelevant, that's why it's hidden by default. Anyways, it cannot be expressed in plain C/H/S for any modern disk.) Disklabel does almost ignore any geometry value at all. Newfs uses a faked geometry of 4096 blocks per cylinder by default, since that proved to be more effective for modern disks. (``Real'' disks like Syquest etc. are the exception these days.) All you really ought to know is the overall number of sectors. It is reported for ESDI, IDE, and SCSI disks at boot time. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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