From owner-freebsd-scsi Fri Mar 12 0:50:58 1999 Delivered-To: freebsd-scsi@freebsd.org Received: from verdi.nethelp.no (verdi.nethelp.no [158.36.41.162]) by hub.freebsd.org (Postfix) with SMTP id 6E83314D9A for ; Fri, 12 Mar 1999 00:50:01 -0800 (PST) (envelope-from sthaug@nethelp.no) Received: (qmail 3238 invoked by uid 1001); 12 Mar 1999 08:43:01 +0000 (GMT) To: cc@137.org Cc: freebsd-scsi@freebsd.org Subject: Re: SCSI disk oddities and Buslogic problems.. From: sthaug@nethelp.no In-Reply-To: Your message of "Fri, 12 Mar 1999 01:16:30 -0600" References: <19990312071630.5163DB1@friley-185-205.res.iastate.edu> X-Mailer: Mew version 1.05+ on Emacs 19.34.2 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Date: Fri, 12 Mar 1999 09:43:00 +0100 Message-ID: <3236.921228180@verdi.nethelp.no> Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > I recently purchased a two new disks, and have noticed some odd behavior. > The drives are IBM DDRS-34560D's. Anyways, whenever I get new disks, I > like to benchmark them. > > In this case, I have found that while running the following commands that > the data transfer is very erratic. > > dd if=/dev/rda2s3 of=/dev/null bs=128k (or any place on the disk..) > > iostat -w 1 da2 > > Are the statistics output by iostat accurate? The values output by iostat > usually range from 4 to 9MB/s for the DDRS drives. Although it seems > random, it it is consistent in the same place on the drives. Does anyone > else have any input on the DDRS drives? I'm sure it is harmless, but I > can't help but to be bothered by this behavior.. da0: Fixed Direct Access SCSI-2 device da0: 80.000MB/s transfers (40.000MHz, offset 15, 16bit), Tagged Queueing Enabled da0: 8715MB (17850000 512 byte sectors: 255H 63S/T 1111C) No problem with a 9 GB model here. Typical iostat output: tty da0 da1 wd0 cpu tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id 0 229 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 2 0 98 0 76 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 0 0100 0 76 64.00 205 12.81 0.00 0 0.00 0.00 0 0.00 0 0 1 0 99 0 76 64.00 204 12.75 0.00 0 0.00 0.00 0 0.00 0 0 2 0 98 0 76 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 2 0 98 0 76 64.00 205 12.81 0.00 0 0.00 0.00 0 0.00 0 0 0 0100 0 76 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 1 1 98 0 76 64.00 204 12.75 0.00 0 0.00 0.00 0 0.00 0 0 2 1 98 0 76 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 2 1 97 0 76 64.00 205 12.81 0.00 0 0.00 0.00 0 0.00 0 0 0 1 99 0 76 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 1 0 99 0 76 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 1 1 98 0 76 64.00 205 12.81 0.00 0 0.00 0.00 0 0.00 0 0 2 0 98 0 76 64.00 206 12.87 0.00 0 0.00 0.00 0 0.00 0 0 2 0 98 seems to correspond pretty well with the numbers from dd (multiple runs): # dd if=/dev/rda0s1 of=/dev/null bs=128k count=4096 536870912 bytes transferred in 39.885097 secs (13460439 bytes/sec) 536870912 bytes transferred in 40.334386 secs (13310502 bytes/sec) 536870912 bytes transferred in 39.890058 secs (13458765 bytes/sec) This is with an Adaptec 7890 U2W onboard controller. Steinar Haug, Nethelp consulting, sthaug@nethelp.no To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message