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Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!decwrl!rtech!amdahl!amdahl!agc From: agc@uts.amdahl.com (Alistair G. Crooks) Newsgroups: comp.os.386bsd.questions Subject: Re: Problems with NetBSD-08 and ESDI - Please help! Summary: The PC BIOS sucks Message-ID: <5d3J03pYd8aM00@amdahl.uts.amdahl.com> Date: 10 Aug 93 07:34:10 GMT References: <244ule$cke@netbsd08.telecom.com.au> Organization: Amdahl Corporation, Sunnyvale CA Lines: 51 In article <244ule$cke@netbsd08.telecom.com.au> tdwyer@netbsd08.telecom.com.au (Terry Dwyer 491 5161) writes: > >After having installed NetBSD-08 on two 486's with Adaptec 1542B SCSI >controllers, I thought I would not have too many problems installing >on a 486 with a Western Digital WD1007V ESDI controller. Boy, was I >wrong. The drive is a WREN V 94186-383H. Translation has been turned >off. I have tried alternate sector mapping on and off, set the drive SPT >(according to manufacturers specs) to 34 and 36, used the ESDI bios to >low level format the drive, and WDFMT (a WD utility), to do the same. >There is a difference in the way the formatters work - the BIOS utility >appears to replace every bad sector found with a sector it maps in from >the last two cylinders of the drive hence moving sectors to a different >rack on the disk. The WDFMT util seems to mark the bad sectors (in place), >and leaves the drive geometry alone. Needless to say, none of the above >work, and all fail consistently with write errors. It seems that NetBSD >is not paying any attention to any bad sector mapping done by either of >the WD formatters. When installing NetBSD, I've tried a y and an n reply >to the question about automatic bad sector forwarding, results were the same >both times, with bad sectors being found either during install or when copying >the distribution onto the drive. > > Any ideas? > >Terry. You seem to be having the same problem that I've got with an "IDE" drive that refuses to forward bad sectors automatically. Basically, you've got a disc with 1747 (I think) cylinders, but the BIOS puts an upper limit of 1024 sectors on the number of cylinders you can have. This doesn't matter for real IDE discs, or for SCSIs, which do their bad sector forwarding automatically, but fails for ESDI and st506s, which use bad144 to do the bad sector forwarding. This puts the bad sector information on the last cylinder of the disc (last track for the badsect table, the previous 126 sectors for bad sectors). The NetBSD 0.8 kernel uses the BIOS to read the bad sector table during boot, and so the BIOS translates a "read cylinder 1747" request to a "read cylinder 1024" request, in the mistaken belief that no disc can have more than 1024 cylinders. The best way to get NetBSD 0.8 on your system would be to tell the install program that you've a disc of 1024 cylinders. (That should let you use about 65% of the total space on the disc). Regards, Alistair -- Alistair G. Crooks (agc@uts.amdahl.com) +44 252 346377 Amdahl European HQ, Dogmersfield Park, Hartley Wintney, Hants RG27 8TE, UK. [These are only my opinions, and certainly not those of Amdahl Corporation]