From owner-freebsd-amd64@FreeBSD.ORG Wed Oct 4 14:53:44 2006 Return-Path: X-Original-To: freebsd-amd64@freebsd.org Delivered-To: freebsd-amd64@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A3DF816A416 for ; Wed, 4 Oct 2006 14:53:44 +0000 (UTC) (envelope-from jasen.gibson@ge.com) Received: from ext-ch1gw-6.online-age.net (ext-ch1gw-6.online-age.net [64.37.194.14]) by mx1.FreeBSD.org (Postfix) with ESMTP id A6DFD43D6B for ; Wed, 4 Oct 2006 14:53:37 +0000 (GMT) (envelope-from jasen.gibson@ge.com) Received: from int-ch1gw-5.online-age.net (int-ch1gw-5 [3.159.232.69]) by ext-ch1gw-6.online-age.net (8.13.6/8.13.6/20051111-SVVS-TLS-DNSBL) with ESMTP id k94EqUol008027 for ; Wed, 4 Oct 2006 10:52:30 -0400 Received: from cinmlef10.e2k.ad.ge.com (int-ch1gw-5 [3.159.232.69]) by int-ch1gw-5.online-age.net (8.13.6/8.13.6/20050510-SVVS) with ESMTP id k94EsKxt018781 for ; Wed, 4 Oct 2006 10:54:21 -0400 (EDT) Received: from loumlvem03.e2k.ad.ge.com ([3.159.160.39]) by cinmlef10.e2k.ad.ge.com with Microsoft SMTPSVC(6.0.3790.2499); Wed, 4 Oct 2006 10:53:33 -0400 X-MimeOLE: Produced By Microsoft Exchange V6.0.6603.0 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Date: Wed, 4 Oct 2006 10:53:33 -0400 Message-ID: <888F5D88060A214ABEFED0011CF186620117B916@LOUMLVEM03.e2k.ad.ge.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: suggestions for SATA RAID cards Thread-Index: AcbnxF3Zs9wL0YjUQAeBcKYiX7VuPwAAEtjQ From: "Gibson, Jasen \(GE Indust, ConsInd, consultant\)" To: "Pete French" , X-OriginalArrivalTime: 04 Oct 2006 14:53:33.0856 (UTC) FILETIME=[DD457200:01C6E7C4] Cc: Subject: RE: suggestions for SATA RAID cards X-BeenThere: freebsd-amd64@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to the AMD64 platform List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Oct 2006 14:53:44 -0000 -----Original Message----- From: Pete French [mailto:petefrench@ticketswitch.com] Sent: Wednesday, October 04, 2006 10:50 AM To: freebsd-amd64@freebsd.org; Gibson, Jasen (GE Indust, ConsInd, consultant); killing@multiplay.co.uk Subject: Re: suggestions for SATA RAID cards > I had similar issues as you say with read being much slower than write > using a highpoint controller the fix was to change the default block > size of the array to the min the controller supported. > >Does anyone have a good feel for a blocksize to use on RAID 1 under >FreeBSD ? I know for a system serving pparallel requests the usual = advice >is to have it as large as possible to try and get a single file onto >a single drive, so two in parallel read from a drive each - but for = large >files and a single read, do you want to make it somewhat smaller to = exploit >parallelism between the drives for a single request ? I have a pair of >drives running as RAID 1 and it is fairly obvious that for a large read = it >is alternating between then, rather than reading from both in parallel. >The stripe size there is 64k, what are other people using ? I believe mine is still set at 256k, which may be my issue, if Steven's = suggestion is correct.