From owner-freebsd-performance@FreeBSD.ORG Thu Apr 28 16:08:52 2005 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A3D9D16A4F8 for ; Thu, 28 Apr 2005 16:08:52 +0000 (GMT) Received: from multiplay.co.uk (www1.multiplay.co.uk [212.42.16.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id 03CFF43D41 for ; Thu, 28 Apr 2005 16:08:52 +0000 (GMT) (envelope-from killing@multiplay.co.uk) Received: from stevenp4 ([193.123.241.40]) by multiplay.co.uk (multiplay.co.uk [212.42.16.7]) (MDaemon.PRO.v8.0.1.R) with ESMTP id md50001366916.msg for ; Thu, 28 Apr 2005 17:04:44 +0100 Message-ID: <070d01c54c0c$79550260$7f06000a@int.mediasurface.com> From: "Steven Hartland" To: "Eric Anderson" References: <069901c54bfd$2967ba40$7f06000a@int.mediasurface.com> <4270F648.5030501@centtech.com> <06d301c54c02$98ab5ce0$7f06000a@int.mediasurface.com> <42710594.2010308@centtech.com> Date: Thu, 28 Apr 2005 17:08:10 +0100 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2527 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527 X-Spam-Processed: multiplay.co.uk, Thu, 28 Apr 2005 17:04:44 +0100 (not processed: message from valid local sender) X-MDRemoteIP: 193.123.241.40 X-Return-Path: killing@multiplay.co.uk X-MDaemon-Deliver-To: freebsd-performance@freebsd.org X-MDAV-Processed: multiplay.co.uk, Thu, 28 Apr 2005 17:04:46 +0100 cc: freebsd-performance@freebsd.org Subject: Re: Very low disk performance Highpoint 1820a X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Apr 2005 16:08:52 -0000 ----- Original Message ----- From: "Eric Anderson" > Correct - I misread the dd line. When you are doing the dd, what is > your system busy doing? (top/ps info) The machine is idle only me doing the test via an ssh session. > What do you suspect? I really dont know what it could be driver issue? iirc scott wrote / converted this one from source direct form highpoint so maybe he could have some useful imput here. > Some info from one of my arrays: > > # dd if=/dev/zero of=./testfile bs=64k count=10000 > 10000+0 records in > 10000+0 records out > 655360000 bytes transferred in 3.581413 secs (182989226 bytes/sec) > > (unmount / mount filesystem) > # dd if=./testfile of=/dev/null bs=64k count=10000 > 10000+0 records in > 10000+0 records out > 655360000 bytes transferred in 6.747707 secs (97123362 bytes/sec) > > # dd if=/dev/da0s1d of=/dev/null bs=64k count=10000 > 10000+0 records in > 10000+0 records out > 655360000 bytes transferred in 11.252226 secs (58242699 bytes/sec) > > Seems like the reads should be faster than the writes.. Hmm just tried the write and I get: dd if=/dev/zero of=./testfile bs=64k count=10000 10000+0 records in 10000+0 records out 655360000 bytes transferred in 5.237026 secs (125139727 bytes/sec) Which is 2.5 times quicker than read which is really just not right. Issue with /dev/null? Steve / K ================================================ This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. In the event of misdirection, illegible or incomplete transmission please telephone (023) 8024 3137 or return the E.mail to postmaster@multiplay.co.uk.