From owner-freebsd-current@FreeBSD.ORG Sun Jun 20 18:50:07 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 878BE1065673 for ; Sun, 20 Jun 2010 18:50:07 +0000 (UTC) (envelope-from scottl@samsco.org) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.freebsd.org (Postfix) with ESMTP id 23E438FC0C for ; Sun, 20 Jun 2010 18:50:06 +0000 (UTC) Received: from [127.0.0.1] (pooker.samsco.org [168.103.85.57]) (authenticated bits=0) by pooker.samsco.org (8.14.4/8.14.4) with ESMTP id o5KIo38Z011469; Sun, 20 Jun 2010 12:50:03 -0600 (MDT) (envelope-from scottl@samsco.org) Mime-Version: 1.0 (Apple Message framework v1078) Content-Type: text/plain; charset=us-ascii From: Scott Long X-Priority: 3 In-Reply-To: <0B4F09B43AE84F24954E3B940FA0ECBB@multiplay.co.uk> Date: Sun, 20 Jun 2010 12:50:03 -0600 Content-Transfer-Encoding: quoted-printable Message-Id: References: <4C1AB4C0.4020604@freemail.hu> <4C1B3792.9000007@freemail.hu><4C1C0ED9.8090103@freemail.hu> <2F904ED8-BC95-459F-8536-A889ADDA8D31@samsco.org> <0B4F09B43AE84F24954E3B940FA0ECBB@multiplay.co.uk> To: "Steven Hartland" X-Mailer: Apple Mail (2.1078) X-Spam-Status: No, score=-50.0 required=3.8 tests=ALL_TRUSTED, T_RP_MATCHES_RCVD autolearn=unavailable version=3.3.0 X-Spam-Checker-Version: SpamAssassin 3.3.0 (2010-01-18) on pooker.samsco.org Cc: oizs , freebsd-current@freebsd.org Subject: Re: Dell Perc 5/i Performance issues X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 20 Jun 2010 18:50:07 -0000 I just set up a machine with the following GPT scheme: =3D> 34 5853511613 mfid0 GPT (2.7T) 34 128 1 freebsd-boot (64K) 162 862 - free - (431K) 1024 2097152 2 freebsd-ufs (1.0G) 2098176 4194304 3 freebsd-swap (2.0G) 6292480 2097152 4 freebsd-ufs (1.0G) 8389632 104857600 5 freebsd-ufs (50G) 113247232 5740264414 6 freebsd-ufs (2.7T) 5853511646 1 - free - (512B) After the first partition, I created a deliberate gap for alignment, = reflected in the second line. The third line shows a starting offset of = sector 1024, which is 512KB. This should be a good generic start point = for most RAID geometries with a stripe size <=3D 512KB. The rest are = normal /, swap, /var, /usr and /opt partitions. The single free sector = on the final line is probably a calculation error on my part, there's no = particular reason for it. The gpart man page has good descriptions on how to create partitions and = make the GPT scheme bootable. It's not very automated, you'll need to = have a calculator handy, but it works. Scott On Jun 20, 2010, at 12:20 PM, Steven Hartland wrote: > Does anyone know of a nice how to guide for achieving this? >=20 > ----- Original Message ----- From: "Scott Long" > 2. Partition alignment. If you're using classic MBR slices, = everything gets misaligned by 63 sectors, making it impossible for the = controller to optimize both reads and writes. If the array is used for = secondary storage, simply don't use an MBR scheme. If it's used for = primary storage, try using GPT instead and setting up your partitions so = that they are aligned to large power-of-2 boundaries. >=20 >=20 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > 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.=20 > In the event of misdirection, illegible or incomplete transmission = please telephone +44 845 868 1337 > or return the E.mail to postmaster@multiplay.co.uk. >=20