Risc System/6000

jim frost madd at world.std.com
Fri Mar 9 12:29:31 AEST 1990


pcg at 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 at saber.com



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