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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.mel.connect.com.au!news.syd.connect.com.au!news.bri.connect.com.au!fjholden.OntheNet.com.au!not-for-mail From: Tony Griffiths <tonyg@OntheNet.com.au> Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: SCSI termination and performance tweaking Date: Sun, 20 Apr 1997 12:17:47 +1000 Organization: On the Net (ISP on the Gold Coast, Australia) Lines: 38 Message-ID: <33597CCB.BAD@OntheNet.com.au> References: <01bc4bbf$a46265c0$9e4f96cd@domains> Reply-To: tonyg@OntheNet.com.au NNTP-Posting-Host: swanee.nt.com.au Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0 (WinNT; I) To: Admin <kschafer@cyberbeach.net> Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:39387 Admin wrote: > > I'm exploring a dual drive machine running under FreeBSD 2.2.1R > > Both are SCSI Ultra-Wide drives, namely a seagate 2gig Hawk and a 4gig > Barracuda. > > I did some test copies between drives and the results were so so. A 50meg > binary file took about 13 seconds to copy from the barracuda to the hawk. What you have essentially tested is filesystem performance, NOT disk drive performance (to a large extent at least)!!! To test drive performance, you need to 'dd' from one raw partition to another, not 'cp' a file from one filesystem to another filesystem... > I'm wonderring if there is something I need to change wrt SCSI termination > or if there is something I need to tweak in FBSD. I very much doubt it. If termination was a problem, then you would be seeing SCSI timeouts and the like being logged on the console and syslog, or worse still, SCSI bus hangs! > > I haven't changed the termination options on either of the drives, both of > which are on the same SCSI bus plugged into an Adaptec 2940UW controller. If their working, leave them alone. Do you testing with 'dd', remembering to use a LARGE (eg. 1M) transfer size otherwise other factors such as rotational latency etc can come into affect. Eg. # dd if=/dev/rsd0e of=/dev/rsd1e bs=1M This assumes that sd1e is a "spare" partition, not a filesystem you want to preserve. ;-) Tony