Path: utzoo!attcan!uunet!rayssd!sud509!heiser@tdw201.ed.ray.com
From: heiser@tdw201.ed.ray.com
Newsgroups: comp.periphs.scsi
Subject: Re: aha1542b and Wren V
Message-ID: <2344@sud509.ed.ray.com>
Date: 6 Sep 90 17:09:26 GMT
References: <1990Aug31.211751.10553@simasd.uucp>
Sender: heiser@sud509.ed.ray.com (Bill Heiser - Unix Sys Admin @ Raytheon Company, Sudbury MA)
Distribution: na
Organization: Raytheon Company, Sudbury MA
Lines: 23

In article <1990Aug31.211751.10553@simasd.uucp> jcurtis@simasd.navy.mil (Jay Curtis) writes:
>
>I recently installed an Adaptec 1542B scsi controller with a Imprimis
>Wren V 385 hard drive.  I am using a 33 MHz 386 with 8 meg ram running
>SCO Xenix 2.3.3.  The Byte Unix benchmarks show a thoughput of less than
>100K bytes/sec for sustained reads/rights/copies.  I suspect that the
>drive read ahead is turned off but have no way of verifying this.  What

I was told by a Unix consultant that 'read ahead cache' should NOT
be enabled on Unix systems.  This has something to do with the fact
that Unix does its own caching (buffering), and if the drive does
caching too, things could get confused in case of a power failure.



-- 
Bill Heiser
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