From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id A4DE81381F3 for ; Thu, 20 Jun 2013 19:27:13 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 43018E0A92; Thu, 20 Jun 2013 19:27:11 +0000 (UTC) Received: from mail-vb0-f50.google.com (mail-vb0-f50.google.com [209.85.212.50]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 7A7DFE09A9 for ; Thu, 20 Jun 2013 19:27:10 +0000 (UTC) Received: by mail-vb0-f50.google.com with SMTP id w16so4964385vbb.23 for ; Thu, 20 Jun 2013 12:27:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; bh=T6/lh5vA7myExNaNiFYvwpd1uy67Us8U0Y0dxcL1eKQ=; b=jEXSKcPVC+j9AGajQ4CuJX/fyf0tbfBsmXCw0szh3zrKMEA6Hzcgc8kGaHOBc0xMG8 oK55JZCm6v0ZTAYcf/3m78o+B+coOqLuYOahHkSNGLtmbNgYSNVgtjqKbulvorCvbZr7 WvmSbFOjZQUnbM/biuc9z0Qq36F3IuDwxjWrj2fz6U5goHhsnhK61j5P2OjBNIflNNmj E4/LShb1XcHDBajxKxMa2KCzakXvHjMTKknu2kLYBTTWnAs3RNCqK3qno5R3zlvNRj+X LfA90Q0A5Ozltzqys2pNdICAQBubxlD6+7rEeFPBHJlRrFltZh1beIZlWQiiaVrSeOud 9EjA== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-amd64@lists.gentoo.org Reply-to: gentoo-amd64@lists.gentoo.org MIME-Version: 1.0 X-Received: by 10.58.69.65 with SMTP id c1mr3821749veu.88.1371756429633; Thu, 20 Jun 2013 12:27:09 -0700 (PDT) Sender: freemanrich@gmail.com Received: by 10.52.73.3 with HTTP; Thu, 20 Jun 2013 12:27:09 -0700 (PDT) In-Reply-To: References: Date: Thu, 20 Jun 2013 15:27:09 -0400 X-Google-Sender-Auth: 49QdNzSALjuRXCpcj85Mp6HELmg Message-ID: Subject: Re: [gentoo-amd64] Is my RAID performance bad possibly due to starting sector value? From: Rich Freeman To: gentoo-amd64@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 X-Archives-Salt: 9ca2d4af-515a-438b-af0d-745fa5d064d5 X-Archives-Hash: 8adb34681554dcf4e1c5f9390003fe28 On Thu, Jun 20, 2013 at 3:10 PM, Mark Knecht wrote: > Looking for some thoughtful ideas from those more experienced in this area. Please do share your findings. I suspect my own RAID+LVM+EXT3/4 system is not optimized - especially with LVM I have no idea how blocks in ext3/4 end up mapping to stripes and physical blocks. Oh, and this is on 4k disks. Honestly, this is one of the reasons I REALLY want to move to btrfs when it fully supports raid5. Right now the various layers don't talk to each other and that means a lot of micro-management if you don't want a lot of read-write-read cycles (to say nothing of what you can buy with a filesystem that can aim to overwrite entire stripes at a time). Rich