Xref: utzoo comp.periphs.scsi:1290 comp.unix.sysv386:1816
Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!cica!iuvax!news!cartan!ndmath!nstar!larry
From: larry@nstar.uucp (Larry Snyder)
Newsgroups: comp.periphs.scsi,comp.unix.sysv386
Subject: Re: parameters on CDC Wren IV, Adaptec 1542b
Message-ID: <1990Nov04.004934.232@nstar.uucp>
Date: 4 Nov 90 00:49:34 GMT
References: <1990Nov3.185524.468@unixland.uucp>
Organization: Northern Star Communications, Limited
Lines: 52

bill@unixland.uucp (Bill Heiser) writes:

>I ran the SCSICNTL.EXE program to examine my CDC Wren IV (hooked up
>to an Adaptec 1542b), and have some questions about the appropriate 
>settings.  The system is running Esix Rev D (SYSVR3 Unix).

>Parameters:

>                       Defaults      Current     Options

>Disable Correction     enabled       enabled
>Transfer on error      enabled       enabled
>post error             disabled      disabled
>early error correction disabled      disabled
>read continuous        disabled      disabled
>transfer block         disabled      disabled
>auto read allocation   disabled      disabled
>auto write allocation  disabled      disabled
>retry count               27           27        1-255
>buffer full ratio          4            4        0-255
>buffer empty ratio         4            4        0-255
>[a bunch of stuff about tracks/sectors per zone skipped for now]
>write index enable     disabled      disabled
>cache enable           disabled      disabled


>What are the best settings to have on these parameters in my application?

what you need to do is to change one item at a time - then
bench the system, change another - then bench, etc..   

I have cache enabled (made a 10% difference) and changed the
buffer ratios from 4 to 16 (made a + difference on large disk IO,
and - on small; but since most of mine is large - I changed it)..




>Thanks in advance...

>Bill

>-- 
>home:	...!{uunet,bloom-beacon,esegue}!world!unixland!bill
>	bill@unixland.uucp,  bill%unixland.uucp@world.std.com
>	Public Access Unix  - Esix SYSVR3 - (508) 655-3848
>other:	heiser@world.std.com   Public Access Unix (617) 739-9753
-- 
       Larry Snyder, Northern Star Communications, Notre Dame, IN USA 
 {larry@nstar, uunet!sco!romed!nstar!larry, nstar%larry@iuvax.cs.indiana.edu}
                     backbone usenet newsfeeds available
         Public Access Unix Site (219) 289-0282 (5 high speed lines)