From owner-freebsd-performance@FreeBSD.ORG Thu Apr 28 14:58:26 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 7E45216A4CF for ; Thu, 28 Apr 2005 14:58:26 +0000 (GMT) Received: from multiplay.co.uk (www1.multiplay.co.uk [212.42.16.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id D522D43D41 for ; Thu, 28 Apr 2005 14:58:25 +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 md50001366716.msg for ; Thu, 28 Apr 2005 15:54:01 +0100 Message-ID: <06d301c54c02$98ab5ce0$7f06000a@int.mediasurface.com> From: "Steven Hartland" To: "Eric Anderson" References: <069901c54bfd$2967ba40$7f06000a@int.mediasurface.com> <4270F648.5030501@centtech.com> Date: Thu, 28 Apr 2005 15:57:28 +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 15:54:01 +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 15:54:02 +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 14:58:26 -0000 ----- Original Message ----- From: "Eric Anderson" >> Where do I start looking? > First, understand that RAID 5 is dependant on fast hardware to performa > the XOR operations. A single disk without any RAID can easily > outperform a RAID array if the RAID array is on a 'slow' controller. > The Highpoint controllers are not exactly high-end fast RAID > controllers, so ~50MB/s isn't too bad for that I would say. Did you > happen to try a vinum RAID5? How about a stripe? The quoted benchmarks for this controller are ~500MB/s with 8 raptor disks. Its a hardware RAID 5 with 8 SATA channels on 64Bit PCI-X @ 133Mhz so under the current setup it should be achieving ~250MB/s Im only getting 50MB/s which is just silly. It was also my inderstanding that the XOR is only done on write not read. > You could make two RAID 5's with the controller, and then stripe those > in vinum. You could also do a combo of two stripes in the controller, > and a vinum mirror in FreeBSD - that would give you decent performance. I could but it seems there is something more problematic a foot here and would like to investigate the reason for the poor performance not workaround it. Steve ================================================ 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.