From owner-svn-src-all@FreeBSD.ORG Mon Dec 6 21:23:17 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 0CD2A106564A; Mon, 6 Dec 2010 21:23:17 +0000 (UTC) (envelope-from ivoras@gmail.com) Received: from mail-qw0-f50.google.com (mail-qw0-f50.google.com [209.85.216.50]) by mx1.freebsd.org (Postfix) with ESMTP id 5DFEB8FC18; Mon, 6 Dec 2010 21:23:15 +0000 (UTC) Received: by qwd6 with SMTP id 6so1799570qwd.37 for ; Mon, 06 Dec 2010 13:23:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:sender:received :in-reply-to:references:from:date:x-google-sender-auth:message-id :subject:to:cc:content-type:content-transfer-encoding; bh=n9Mm3vFyIDneV3G5HHGHDuofN8GKJfFvA8a3lQLILnQ=; b=U3FxDzpP+Rat8RDFC8TAI4n0IncQVF+n3xFeSTstfsJInJKUuMiqeqMQw//HcOmZo5 XRtACN85CFXQWMgSeMqsB8odkQYijzI+Y+cSdZb8brJd5DKr667YT6sQVyKKpXiu8jOq P4oxRW1hQ5lGJzNedRW5IbPm9M2ObiFdDMPKw= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type :content-transfer-encoding; b=YRNMf4eOYgVxvEi6ll+ZC46I53hqgtax+0FCYNhgqHGkNIfKx/DOXEiSPp3ytboB7f 62UWE2/P8k4bV0ZRhZ7gy0eswCW89KfNSev7ENB48X2m9bxmpU0izyPV2tNQQH1WRXJg M2L8dzdreh1Qg9kDrdlL9G7e9bFeEzjZeS0Ro= Received: by 10.229.212.5 with SMTP id gq5mr4782566qcb.275.1291670595472; Mon, 06 Dec 2010 13:23:15 -0800 (PST) MIME-Version: 1.0 Sender: ivoras@gmail.com Received: by 10.229.231.143 with HTTP; Mon, 6 Dec 2010 13:22:35 -0800 (PST) In-Reply-To: <20101206211607.GA65110@muon.cran.org.uk> References: <201012061218.oB6CI3oW032770@svn.freebsd.org> <20101206195327.GD1936@garage.freebsd.pl> <201012061518.49835.jhb@freebsd.org> <20101206211607.GA65110@muon.cran.org.uk> From: Ivan Voras Date: Mon, 6 Dec 2010 22:22:35 +0100 X-Google-Sender-Auth: Y9FPzTYYPnbIaKl3gBHFHx1N-U0 Message-ID: To: Bruce Cran Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Pawel Jakub Dawidek , John Baldwin 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 21:23:17 -0000 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 =C2=A0Sector size: =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 512 bytes >> Physical Sector size: =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A04096 bytes >> device size with M =3D 1024*1024: =C2=A0 =C2=A0 1430799 MBytes >> device size with M =3D 1000*1000: =C2=A0 =C2=A0 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. > # camcontrol identify /dev/ada1 > ... > device model =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0WDC WD10EARS-00Z5B1 > ... > sector size =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 logical 512, physic= al 512, offset 0 Agreed. Some drives lie.