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Newsgroups: comp.unix.bsd Path: sserve!manuel.anu.edu.au!munnari.oz.au!sgiblab!darwin.sura.net!Sirius.dfn.de!mailgzrz.TU-Berlin.DE!news.netmbx.de!Germany.EU.net!mcsun!inesc.inesc.pt!pombo!rps From: rps@pombo.inescc.pt (Rui Pedro Salgueiro) Subject: Re: Finding untranslated params for IDE drives (w/ pgm) Message-ID: <1992Oct22.184322.19542@pombo.inescc.pt> Organization: INESC - Nucleo de Coimbra X-Newsreader: Tin 1.1 PL3 References: <1c069hINNimd@maverick.ksu.ksu.edu> Date: Thu, 22 Oct 1992 18:43:22 GMT Lines: 34 brtmac@maverick.ksu.ksu.edu (Brett McCoy) writes: : One reason to turn off translation is so that that all the fancy : Berkeley Fast File System stuff can do it's thing. All the : calculations that it does don't mean a thing if the geometry is : getting translated. Now, the MAXTOR 7120A throws a kink in this. I don't think you can turn off translation in a modern disk. If I'm not mistaken most modern disks have a variable number of sectors per track (they use something called ZBR (Zoned Bit Recording ???)). The outer tracks have more sectors than the inner ones in order to have more capacity and transfer rate. In the seagate catalogue the information to most disks is only the number of heads and cylinders and the total capacity. Also these disks have a variable internal transfer rate, and, as they have a fixed rotation speed, they must have a variable number of sectors/track. So, any geometry in the form: heads/cylinders/sectors has to be translated. I think the vision the system has of the disks should be changed to just a linear array of blocks. That's the way SCSI works. Disclaimer: I'm not a expert on disks, altought I have read a lot of specs lately. I'm not a expert on the FFS altought I have teached it in an INTRODUCTION course in Operating Systems. Rui Salgueiro | Dpt. de Matematica | Safe sex doesn't mean no E-Mail: rps@inescc.pt | Universidade de Coimbra | sex, it just means use your clcmat@ciuc2.uc.pt | Portugal | imagination - Billy Bragg rps@mat.uc.pt RSN | A guest @ Inesc Coimbra |