Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 7003D9FB961 for ; Sat, 2 Jun 2007 02:41:30 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 78058-01 for ; Sat, 2 Jun 2007 02:41:28 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from exprod6og56.obsmtp.com (exprod6og56.obsmtp.com [64.18.1.208]) by postgresql.org (Postfix) with SMTP id 4D3539FB926 for ; Sat, 2 Jun 2007 02:41:29 -0300 (ADT) Received: from source ([63.240.6.44]) (using TLSv1) by exprod6ob56.postini.com ([64.18.5.12]) with SMTP; Fri, 01 Jun 2007 22:41:14 PDT Received: from 172.16.1.110 by mail.mi8.com with ESMTP (- Welcome to Mi8 Corporation www.Mi8.com (D4)); Sat, 02 Jun 2007 01:41:08 -0400 X-Server-Uuid: C8FB4D43-1108-484A-A898-3CBCC7906230 Received: from MI8NYCMAIL08.Mi8.com ([172.16.1.165]) by D01SMTP01.Mi8.com with Microsoft SMTPSVC(6.0.3790.1830); Sat, 2 Jun 2007 01:41:08 -0400 Received: from 24.23.197.133 ([24.23.197.133]) by MI8NYCMAIL08.Mi8.com ( [172.16.1.190]) via Exchange Front-End Server mi8owa.mi8.com ( [172.16.1.104]) with Microsoft Exchange Server HTTP-DAV ; Sat, 2 Jun 2007 05:41:08 +0000 User-Agent: Microsoft-Entourage/11.3.3.061214 Date: Fri, 01 Jun 2007 22:41:07 -0700 Subject: Re: Autodetect of software RAID1+0 fails From: "Luke Lonergan" To: "Steinar H. Gunderson" , "Craig James" cc: pgsql-performance@postgresql.org Message-ID: Thread-Topic: [PERFORM] Autodetect of software RAID1+0 fails Thread-Index: Acek2J3C3C4wJhDLEdyMXAAX8s8Cag== In-Reply-To: <20070601213501.GA23940@uio.no> MIME-Version: 1.0 X-OriginalArrivalTime: 02 Jun 2007 05:41:08.0521 (UTC) FILETIME=[9EAA7190:01C7A4D8] X-WSS-ID: 6A7FDD7E1AG16170185-01-01 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200706/9 X-Sequence-Number: 25042 Steinar, On 6/1/07 2:35 PM, "Steinar H. Gunderson" wrote: > Either do your md discovery in userspace via mdadm (your distribution can > probably help you with this), or simply use the raid10 module instead of > building raid1+0 yourself. I found md raid10 to be *very* slow compared to raid1+0 on Linux 2.6.9 -> 2.6.18. Very slow in this case is < 400 MB/s compared to 1,800 MB/s. - Luke