Date: Thu, 25 May 1995 13:57:05 -0700 (PDT) From: Poul-Henning Kamp <phk@ref.tfs.com> To: gene@starkhome.cs.sunysb.edu (Gene Stark) Cc: cs.weber.edu!terry@sbstark.cs.sunysb.edu, blaise.ibp.fr!roberto@sbstark.cs.sunysb.edu, FreeBSD.org!current@sbstark.cs.sunysb.edu Subject: Re: newfs weirdness... Message-ID: <199505252057.NAA27958@ref.tfs.com> In-Reply-To: <199505251818.OAA11883@starkhome.cs.sunysb.edu> from "Gene Stark" at May 25, 95 02:18:34 pm
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> The sticking point for me is that it is just as wrong to newfs a UFS > filesystem with a fictitious BIOS geometry as it is to newfs it with a > 4096/1 geometry. Using the fictitious BIOS geometry at least has the > advantage that an integral number of cylinder groups fit into the > partition, so you are not wasting a few thousand sectors at the end > of the partition. Also, the "real" geometries supplied by the drives > generally have a nice relationship to the fictitious BIOS geometries, > so that again you get an integral number of cylinder groups in the > partition. I have a patch for that "feature" which will go in after 2.0.5 is out. For now it lives in sysinstall of 2.0.5. The trick is to find a number in the general range of 2048..4096 which divides into the number of sectors on the partition. > In the absence of information to the contrary, for an IDE drive it seems > to me that the best available information is that which is supplied by the > drive. Barring that, what is in the disklabel is next best. I can't > possibly see why a 4096/1 geometry is going to be uniformly better than > these other choices. Plus you have to go to extra trouble to avoid > wasting sectors and getting the warning message. You may waste a lot more space using the IDE geometry than by the 4096/1 because you may get TONS of superblocks for even very small disks... -- Poul-Henning Kamp <phk@login.dknet.dk> -- TRW Financial Systems, Inc. 'All relevant people are pertinent' && 'All rude people are impertinent' => 'no rude people are relevant'
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