From owner-svn-src-all@FreeBSD.ORG Mon Dec 6 22:30:49 2010 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id ADDD61065673; Mon, 6 Dec 2010 22:30:49 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 7E3D18FC26; Mon, 6 Dec 2010 22:30:49 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 1C4A346B0C; Mon, 6 Dec 2010 17:30:49 -0500 (EST) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 9D99D8A009; Mon, 6 Dec 2010 17:30:47 -0500 (EST) From: John Baldwin To: Ivan Voras Date: Mon, 6 Dec 2010 17:00:48 -0500 User-Agent: KMail/1.13.5 (FreeBSD/7.3-CBSD-20101102; KDE/4.4.5; amd64; ; ) References: <201012061218.oB6CI3oW032770@svn.freebsd.org> <20101206211607.GA65110@muon.cran.org.uk> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201012061700.49219.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (bigwig.baldwin.cx); Mon, 06 Dec 2010 17:30:47 -0500 (EST) X-Virus-Scanned: clamav-milter 0.96.3 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-1.9 required=4.2 tests=BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on bigwig.baldwin.cx Cc: Bruce Cran , svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Pawel Jakub Dawidek Subject: Re: svn commit: r216230 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Dec 2010 22:30:49 -0000 On Monday, December 06, 2010 4:22:35 pm Ivan Voras wrote: > On 6 December 2010 22:16, Bruce Cran wrote: > > On Mon, Dec 06, 2010 at 09:31:39PM +0100, Ivan Voras wrote: > >> For what it's worth, apparently linux has the concept of "physical" > >> and "logical" sector sizes (possibly in addition to "stripe size"), > >> with physical being 4096 and logical 512, for example: > >> > >> # hdparm -I /dev/sde | grep size > >> Logical Sector size: 512 bytes > >> Physical Sector size: 4096 bytes > >> device size with M = 1024*1024: 1430799 MBytes > >> device size with M = 1000*1000: 1500301 MBytes (1500 GB) > > > > So do we, except they're both the same for Advanced Format drives: > > There is a subtle difference here which may be important. We have the > concepts of "sectorsize" and "stripesize". > > I think camcontrol actually reports logical and physical sector sizes > as reported by low-level drivers but currently GEOM names "logical > sector size" as "sectorsize" and "physical sector size" as > "stripesize". > > The term "stripesize" can be overloaded to mean both the item in > question - 4 KiB physical sector sizes and RAID stripe sizes. I think > this situation is bad and that the two meanings should be split. My understanding in GEOM is that the primary meaning for stripe size is for the RAID use case. It is probably the 4K logical sector size that needs to come up with a new field, not vice versa. -- John Baldwin