From owner-freebsd-fs@FreeBSD.ORG Mon Jun 2 09:09:04 2014 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 61409FE5; Mon, 2 Jun 2014 09:09:04 +0000 (UTC) Received: from smtp1.multiplay.co.uk (smtp1.multiplay.co.uk [85.236.96.35]) by mx1.freebsd.org (Postfix) with ESMTP id 207772BA7; Mon, 2 Jun 2014 09:09:03 +0000 (UTC) Received: by smtp1.multiplay.co.uk (Postfix, from userid 65534) id 013E020E7088B; Mon, 2 Jun 2014 09:09:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.multiplay.co.uk X-Spam-Level: ** X-Spam-Status: No, score=2.3 required=8.0 tests=AWL,BAYES_00,DOS_OE_TO_MX, FSL_HELO_NON_FQDN_1,HELO_NO_DOMAIN,RDNS_DYNAMIC,STOX_REPLY_TYPE autolearn=no version=3.3.1 Received: from r2d2 (82-69-141-170.dsl.in-addr.zen.co.uk [82.69.141.170]) by smtp1.multiplay.co.uk (Postfix) with ESMTPS id 1065A20E70886; Mon, 2 Jun 2014 09:08:57 +0000 (UTC) Message-ID: <35E54263991449299DE1F938A3DA83B0@multiplay.co.uk> From: "Steven Hartland" To: "Matthew Ahrens" , "Nathan Whitehorn" References: <20140601004242.GA97224@bewilderbeast.blackhelicopters.org> <3D6974D83AE9495E890D9F3CA654FA94@multiplay.co.uk> <538B4CEF.2030801@freebsd.org> Subject: Re: fdisk(8) vs gpart(8), and gnop Date: Mon, 2 Jun 2014 10:09:02 +0100 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 Cc: freebsd-fs , FreeBSD Hackers , George Wilson X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Jun 2014 09:09:04 -0000 ----- Original Message ----- From: "Matthew Ahrens" > On Sun, Jun 1, 2014 at 8:55 AM, Nathan Whitehorn > wrote: > >> On 06/01/14 08:52, Steven Hartland wrote: >> >>> ----- Original Message ----- From: "Mark Felder" >>> >>> On May 31, 2014, at 20:57, Freddie Cash wrote: >>>> >>>> There's a sysctl where you can set the minimum ashift for zfs. Then you >>>>> never need to use gnop. >>>>> >>>>> I believe it's part of 10.0? >>>>> >>>> >>>> I've not seen this yet. What we need is to port the ability to set >>>> ashift at pool creation time: >>>> >>>> $ zpool create -o ashift=12 tank mirror disk1 disk2 mirror disk3 disk4 >>>> >>>> I believe the Linux zfs port has this functionality now, but we still do >>>> not. >>>> >>> > I am strongly against implementing "-o ashift=12"[*]. If we need to > explicitly tell ZFS what sector size to use, we should make that intention > clear with an appropriately named property, for example "-o > device_sector_size=4K". Even better, this property should be per-disk. > > --matt > > [*] Once we implement an appropriately-named property, I would be OK with > also allowing the "-o ashift=12" as a Linux compatibility feature. Being able to override the detected sector size for a disk would get my vote as that would result in everything else just working and would be able to have different ashift per top level vdev. That said I'm not sure if that should be a ZFS option or just a OS option? IIRC solaris / illumos has that ability already? Regards Steve