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From: madd@world.std.com (jim frost)
Newsgroups: comp.unix.aix,comp.periphs.scsi
Subject: Re: Risc System/6000
Message-ID: <1990Mar9.022931.4674@world.std.com>
Date: 9 Mar 90 02:29:31 GMT
References: <1660@aber-cs.UUCP> <51507@sgi.sgi.com> <PCG.90Mar2184300@rupert.cs.aber.ac.uk>
Organization: Saber Software
Lines: 16

pcg@rupert.cs.aber.ac.uk (Piercarlo Grandi) writes:
>This is the notorious problem that SCSI will hide from the OS the drive
>geometry (down to sector remapping, wich can be really nasty), which of
>course pays put to many nice optimizations.

It's not all that difficult to determine the geometry of a SCSI drive.
During the last USENIX a BSD person who's been researching FS
optimizations which take into account rotational latency hinted that
the BSD people have done so.  What you do with SCSI, then, is run a
geometry analyzer which dumps out the configuration of the SCSI drive
so that the filesystem can do the apropriate optimizations.  No big
trick there.

jim frost
saber software
jimf@saber.com