Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!tut.cis.ohio-state.edu!rutgers!orstcs!sapphire!pvo3366
From: pvo3366@sapphire.OCE.ORST.EDU (Paul O'Neill)
Newsgroups: comp.sys.next
Subject: WrenV caching (Re: Wren V 94181-702 installation)
Keywords: disktab
Message-ID: <15489@orstcs.CS.ORST.EDU>
Date: 5 Feb 90 04:35:17 GMT
References: <15143@orstcs.CS.ORST.EDU> <5059@franz.Franz.COM> <957@wet.UUCP> <15477@orstcs.CS.ORST.EDU>
Sender: usenet@orstcs.CS.ORST.EDU
Reply-To: pvo3366@sapphire.OCE.ORST.EDU (Paul O'Neill)
Organization: Coastal Imaging Lab, Oregon State University, Corvallis, OR
Lines: 28

In article <15477@orstcs.CS.ORST.EDU> pvo3366@sapphire.OCE.ORST.EDU (I) wrote:

>.........................I'm guessing that the operating system is
>not telling the Wren V to use its 32k cache buffer.  Anyone know how
>to do this?
>

Well, gosh, it turns out *I* know how to do this. :-)

Take the Product Specification, mix gently but thoroughly with
	/NextDeveloper/Examples/SCSI/sg_example.c
and the result is
	cachecon.c

I just ftp'ed it to the cs.orst.edu archives as WrenV_cache.tar.Z.

Speed of sequential reads measured by the 'disk' program has gone
from 250 KB/s to 350 KB/s.

It looks like it may work on Wren IV's, also.

Now all we have to do is figure out this rotational latency stuff.  Help!!


Paul O'Neill                 pvo@oce.orst.edu
Coastal Imaging Lab
OSU--Oceanography
Corvallis, OR  97331         503-737-3251