Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!rutgers!usc!snorkelwacker!ira.uka.de!smurf!urlichs From: urlichs@smurf.sub.org (Matthias Urlichs) Newsgroups: comp.unix.aux Subject: Re: Disk geometry and /etc/disktab Message-ID: Date: 7 Jul 90 00:35:07 GMT References: <2698@dftsrv.gsfc.nasa.gov> Organization: University of Karlsruhe, FRG Lines: 30 In comp.unix.aux, article <2698@dftsrv.gsfc.nasa.gov>, jim@jagmac2.gsfc.nasa.gov (Jim Jagielski) writes: < The characteristics of a disk drive's geometry needs to be included in A/UX < 2.0 /etc/disktab file. Side question: Are these values used for anything, or are they just there for performance reasons (mkfs for a BSD file system)? Why can't these utilities pretty please _ask_ the SCSI drive, instead of pestering us poor clueless users with maintaining that stuff? And what, if anything, are we to do with drives which have a variable number of sectors (depending on the track)? < There are two ways of getting this information: either < from SCSI Evaluator OR LaCie SilverLining. < < My trouble is that both return DIFFERENT values for the number of cylinders < for all my hard disks. Which should I believe? For example, for my Quantum < 80 (the newer 3 1/2 inch) SCSI Eval. returns 834 cylnders, whereas SL returns < 837 (and 6 heads, 32 sectors/track)... (SL is 5.24/09 and SCSI Eval is < both 1.00 and 1.03) < It seems that SilverLining includes the spare sectors. Since the SCSI drive doesn't make these available to ordinary mortals (or ordinary file systems), you probably should believe SCSI Evaluator. Disclaimer: Anything I said could be wrong. -- Matthias Urlichs -- urlichs@smurf.sub.org -- urlichs@smurf.ira.uka.de Humboldtstrasse 7 - 7500 Karlsruhe 1 - FRG -- +49+721+621127(Voice)/621227(PEP)