Date: Tue, 24 Jan 1995 10:22:58 -0800 (PST) From: Poul-Henning Kamp <phk@ref.tfs.com> To: terry@cs.weber.edu (Terry Lambert) Cc: bde@zeta.org.au, freebsd-hackers@freefall.cdrom.com, kuku@gilberto.physik.rwth-aachen.de Subject: Re: disklabel (1.1.5.1), partitions Message-ID: <199501241823.KAA21387@ref.tfs.com> In-Reply-To: <9501241804.AA12647@cs.weber.edu> from "Terry Lambert" at Jan 24, 95 11:04:15 am
next in thread | previous in thread | raw e-mail | index | archive | help
> > > Not all SCSI devices are thus translated? > > mostly they are, unless the "> 1GB" option is set. > > Sorry, this isn't really a valid reason for lying about the geometry Hey terry, you lost the reason: A scsi-disk >HAS< no geometry we should care about. > > > Hold on! How about because the kernel should know the real BIOS apparent > > > geometry for instead of making things up like that? > > true, except we cannot trust this one anymore :-( Some IDE and SCSI > > drivers get their "geometry" in CONFIG.SYS these days. > > Actually, most EIDE controllers get them from a modified system boot block > installed by the OEM for the machine. Blowing the system boot block in > that case really screws you up. No, 540Mb and above seems to get it from various "disk-managers" loaded in the config.sys with an increasingly annoying frequency. > I don't understand... what's wrong with: > > Geometry CCCC/HH/SS (Physical CCCC/HH/SS) The Physical isn't true, It's two years since I saw anything which added (multiplied actually) up to the number of sectors available. The numbers are fiction, make belive, has no use, value or connection with our use of the drive. > > Has nothing to do with it. If you pass some of the weird geometries to > > newfs it will become very confused... 32/64 works sensibly most of the > > time. > > This is a bug in newfs, like the one where it doesn't create a lost+found, > not a reason to bogify other parts of the system to hack around it. Not true. Newfs and UFS was optimized to know about disk-geometry. Since most (95%) drives these days are zoned (variable sectors/track), this isn't of any particular use. The existense of caches on the drives doesn't improve it either. All the geometry is really used for is to size the "cylinder"-groups. -- Poul-Henning Kamp <phk@login.dknet.dk> TRW Financial Systems, Inc. FreeBSD has, until now, not one single time had an undetected error. :-)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199501241823.KAA21387>