From owner-freebsd-fs@FreeBSD.ORG Fri Oct 8 02:21:08 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E8E40106566C for ; Fri, 8 Oct 2010 02:21:08 +0000 (UTC) (envelope-from nowak@xpam.de) Received: from mail.csp-systems.de (mail.csp-systems.de [83.246.83.230]) by mx1.freebsd.org (Postfix) with ESMTP id A3DFC8FC0A for ; Fri, 8 Oct 2010 02:21:08 +0000 (UTC) Received: by mail.csp-systems.de (Postfix, from userid 602) id E7B2768F1D7; Fri, 8 Oct 2010 03:53:25 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on mail.csp-systems.de X-Spam-Level: ** X-Spam-Status: No, score=2.9 required=6.0 tests=AWL, BAYES_00, FH_DATE_PAST_20XX, RDNS_NONE autolearn=no version=3.2.5 Received: from master.sinuspl.net (unknown [83.246.67.202]) by mail.csp-systems.de (Postfix) with ESMTP id 46CF568F187 for ; Fri, 8 Oct 2010 03:53:21 +0200 (CEST) Received: by master.sinuspl.net (Postfix, from userid 8) id ACD851080318; Fri, 8 Oct 2010 03:53:20 +0200 (CEST) Received: from [172.19.191.2] (088156221125.bialystok.vectranet.pl [88.156.221.125]) by master.sinuspl.net (Postfix) with ESMTPA id E65F910801AA for ; Fri, 8 Oct 2010 03:53:19 +0200 (CEST) Message-ID: <4CAE798D.6040905@xpam.de> Date: Fri, 08 Oct 2010 03:53:17 +0200 From: Adam Nowacki User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: freebsd-fs@freebsd.org References: <4CAE6C3A.5070509@rcn.com> In-Reply-To: <4CAE6C3A.5070509@rcn.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: ZFS and Samsung Spinpoint F4 4K sector drive X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Oct 2010 02:21:09 -0000 Nothing user friendly but if you're willing to modify sources and rebuild kernel there is a one line tweak. /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c find: *ashift = highbit(MAX(pp->sectorsize, SPA_MINBLOCKSIZE)) - 1; and modify to something like: *ashift = highbit(MAX(MAX(4096, pp->sectorsize), SPA_MINBLOCKSIZE)) - 1; I'm using this for 3 months with 20 2TB 4kb sector WDC disks (in 2 raidz2 arrays of 10) without any issues. Writes go at 300MB/s. Gary Corcoran wrote: > I've tried to read up on the issue of using ZFS with 4K sector drives, > but haven't seen any definitive answers with regards to FreeBSD. > The Samsung Spinpoint F4 is their latest 2TB drive, which has 4K sectors > and "emulation", and no info on whether the emulation can be disabled. > But it is on sale for the next few days, and the price is very tempting. > > So I would like to ask: Can these 4K drives, emulating 512 byte sectors, > be successfully used with ZFS raidz via _some_ tweak, without getting a > major > slowdown? That is, is there some sysctl, some option to zpool create, or > anything else, that can cause a zpool which uses whole disks, to be aligned > to 4K sectors in FreeBSD? > > Thanks, > Gary > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" > >