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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.mel.connect.com.au!news.mira.net.au!news.vbc.net!samba.rahul.net!rahul.net!a2i!news.PBI.net!news.mathworks.com!fu-berlin.de!irz401!orion.sax.de!uriah.heep!news From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Setting geometry important for SCSI disk? Date: 5 Aug 1996 19:55:04 GMT Organization: Private BSD site, Dresden Lines: 32 Message-ID: <4u5jio$62f@uriah.heep.sax.de> References: <4u42l7$ojk@mars.efn.org> Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) NNTP-Posting-Host: localhost.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: knews 0.9.6 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E Michelle Brownsworth <michelle@efn.org> wrote: > I was under the impression that disk geometry was irrelevant and could > safely be ignored when installing on a large SCSI if the entire disk was > to be allocated to FreeBSD. It is, but only if you wouldn't have to rely on the BIOS for loading the BSD bootstrap and the kernel. The closest we can offer you is the ``dangerously dedicated'' mode, where the BSD occupies the entire disk, ignoring all MS-DOS (and other systems) constraints like the necessity to align each fdisk partition (`slice' in FreeBSD terms) on a (ficticous) cylinder boundary. BSD will fill the entire disk right from block 0 to the very last block then. Of course, you still need the BIOS to load the bootstrap, but since the BSD bootstrap starts at block 0 then, the only assumption about the geometry that still holds valid is that the BIOS must have at least 15 sectors (the size of the bootstrap) per track -- this is true for everything that has been seen so far. ``Dangerously dedicated'' is what you get by saying ``A)ll FreeBSD'' in the partition editor, and answering the next question with ``No'' (the non-default answer, to prevent people from stupidly falling into this trap and not knowing later how to get rid of the BSD bootstrap from their MBR ;). -- 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. ;-)