From owner-freebsd-stable@FreeBSD.ORG Tue Jul 19 06:04:16 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E7CCF1065673 for ; Tue, 19 Jul 2011 06:04:15 +0000 (UTC) (envelope-from kob6558@gmail.com) Received: from mail-yw0-f54.google.com (mail-yw0-f54.google.com [209.85.213.54]) by mx1.freebsd.org (Postfix) with ESMTP id A7A228FC1A for ; Tue, 19 Jul 2011 06:04:15 +0000 (UTC) Received: by ywf7 with SMTP id 7so2006796ywf.13 for ; Mon, 18 Jul 2011 23:04:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=OMT2tdYspBOwCAocvcnudlum0ZR/r/9l9jYhRQSNvfg=; b=cuosByW2oLOtQu9M+k8wfzaLgJW3ms4BG+aj0jZhk7nHUIw3UCELuEU8Vg2qLiqFRy a2mfdrM6gqMcq6UIqtDlrkhm4ji4u3rDdcQAgZ1UJVwKSaqNin84q87Kd8ip595Trz9U U1WSiUlIFJNYYt2O7RBIzdyRhVP810IMvRMiE= MIME-Version: 1.0 Received: by 10.150.63.19 with SMTP id l19mr6080398yba.369.1311055454967; Mon, 18 Jul 2011 23:04:14 -0700 (PDT) Received: by 10.151.27.21 with HTTP; Mon, 18 Jul 2011 23:04:14 -0700 (PDT) In-Reply-To: <20110718234124.GA5626@icarus.home.lan> References: <20110718234124.GA5626@icarus.home.lan> Date: Mon, 18 Jul 2011 23:04:14 -0700 Message-ID: From: Kevin Oberman To: Jeremy Chadwick Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-stable@freebsd.org Stable" Subject: Re: Status of support for 4KB disk sectors X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Jul 2011 06:04:16 -0000 On Mon, Jul 18, 2011 at 4:41 PM, Jeremy Chadwick wrote: > On Mon, Jul 18, 2011 at 03:50:15PM -0700, Kevin Oberman wrote: >> I just want to check on the status of 4K sector support in FreeBSD. =A0I= read >> a long thread on the topic from a while back and it looks like I might h= it some >> issues if I'm not REALLY careful. Since I will be keeping the existing W= indows >> installation, I need to be sure that I can set up the disk correctly wit= hout >> screwing up Windows 7. >> >> I was planning on just DDing the W7 slice over, but I am not sure how we= ll this >> would play with GPT. Or should I not try to use GPT at all? I'd like >> to as this laptop >> spreads Windows 7 over two slices and adds a third for the recovery >> system, leaving >> only one for FreeBSD and I'd like to put my files in a separate slice. >> GPT would offer >> that fifth slice. >> >> I have read the handbook and don't see any reference to 4K sectors and o= nly a >> one-liner about gpart(8) and GPT. Oncew I get this all figured out, >> I'll see about writing >> an update about this as GPT looks like the way to go in e future. > > When you say "4KB sector support", what do you mean by this? =A0All > drives on the market as of this writing, that I've seen, all claim a > physical/logical sector size of 512 bytes -- yes, even SSDs, and EARS > drives which we know use 4KB sectors. =A0They do this to guarantee full > compatibility with existing software. > > Since you're talking about gpart and "4KB sector support", did you mean > to ask "what's the state of FreeBSD and aligned partition support to > ensure decent performance with 4KB-sector drives?" > > If so: there have been some commits in recent days to RELENG_8 to help > try to address the shortcomings of the existing utilities and GEOM > infrastructure. =A0Read the most recent commit text carefully: > > http://www.freebsd.org/cgi/cvsweb.cgi/src/sbin/geom/class/part/geom_part.= c > > But the currently "known method" is to use gnop(8). =A0Here's an example: > > http://www.leidinger.net/blog/2011/05/03/another-root-on-zfs-howto-optimi= zed-for-4k-sector-drives/ > > Now, that's for ZFS, but I'm under the impression the exact same is > needed for FFS/UFS. Jeremy, Yes, this is exactly what I mean. If I shell out for a high-end 7200 RPM drive for my laptop only to have it run like a dog. Thanks for the pointers. The first is good news. I'm a bit confused as to w= hat I will need gnop(8) for, but I'll be spending some time reading both the arti= cle and the gnop man page and hopefully that will make it clear. I've only used gpart once and to took way too long to figure out what I needed to do, but it did= work fine. I just wish FreeBSD had some decent documentation on such a fundament= al operation. Fortunately there are some pretty good articles folks have written, but they did leave me with several questions. --=20 R. Kevin Oberman, Network Engineer - Retired E-mail: kob6558@gmail.com