From owner-freebsd-fs@FreeBSD.ORG Wed Jun 13 11:02:33 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 6C480106566C for ; Wed, 13 Jun 2012 11:02:33 +0000 (UTC) (envelope-from i.junus@gmail.com) Received: from mail-we0-f182.google.com (mail-we0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id E80EA8FC14 for ; Wed, 13 Jun 2012 11:02:32 +0000 (UTC) Received: by werg1 with SMTP id g1so461900wer.13 for ; Wed, 13 Jun 2012 04:02:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=JOraypReyVHMyYYNGno01SOppFJuz6ONnc5rX/5jZM4=; b=uiHqq/0sVwLkh9c+7i94Pjkv+N3a9/ZvMyOIOM8KnjOM/V0TAzqZMv0sv9Y++Ll8Nq iRSyaU3G74JsHUahk2ocHjDVv86jicePTYIgM54qBIP8YZbKJOaVO4ThVfZWomWDJFsi bruLgagrs1GGsgdH2B+yr/ZULGKWifJzYK5aaCYNxFAccT9VAblUpjdOeZf0hP7zCeXY EkxVVPSM0C8rT/gSlrJVJ3drNIBf5ymijVBbha2A6GjEbBdaZZp61EZG9uLspbZDMr+8 dnrr/YkEjZ2LHrnLiHmKvPQsig7wT6sU+YuBXmVcxz08lxk/ybvdWdgFUWFGAcX0RuY6 EB9A== MIME-Version: 1.0 Received: by 10.180.78.228 with SMTP id e4mr36921420wix.4.1339585351670; Wed, 13 Jun 2012 04:02:31 -0700 (PDT) Received: by 10.194.33.42 with HTTP; Wed, 13 Jun 2012 04:02:31 -0700 (PDT) In-Reply-To: References: Date: Wed, 13 Jun 2012 19:02:31 +0800 Message-ID: From: Irjohn Junus To: Olivier Smedts Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-fs@freebsd.org Subject: Re: gpart add -a 4096 vs 4k 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: Wed, 13 Jun 2012 11:02:33 -0000 Olivier, Thanks for your quick reply and you're right, '4k' = '8'! # gpart add -t freebsd-zfs -l hdd0 -a 8 da0 da0p1 added # gpart show da0 => 34 3907029101 da0 GPT (1.8T) 34 6 - free - (3.0k) 40 3907029088 1 freebsd-zfs (1.8T) 3907029128 7 - free - (3.5k) Thanks, Ronjns On Wed, Jun 13, 2012 at 6:18 PM, Olivier Smedts wrote: > Hello, > > 2012/6/13 Irjohn Junus : > > Hello, > > > > Relatively new to FreeBSD and learning, I'm trying to partition my HDD > and > > align it to 4k sector. > > > > I do apologize if this has been answered before, I have Googled and read > > gpart(8) man page to no joy. Can anyone please advice why gpart add '-a > > 4096' doesn't yield the same result with '-a 4k'? Many thanks and > captures > > are below. > > > > Regards, > > Ronjns > > > > > > > > #gpart add -t freebsd-zfs -l hdd0 *-a 4096* da0 > > da0p1 added > > # gpart show da0 > > => 34 3907029101 da0 GPT (1.8T) > > 34 4062 - free - (2M) > > *4096 3907022848* 1 freebsd-zfs (1.8T) > > 3907026944 2191 - free - (1.1M) > > > > > > > > # gpart add -t freebsd-zfs -l hdd0 *-a 4k* da0 > > da0p1 added > > # gpart show da0 > > => 34 3907029101 da0 GPT (1.8T) > > 34 6 - free - (3.0k) > > *40 3907029088* 1 freebsd-zfs (1.8T) > > 3907029128 7 - free - (3.5k) > > We're talking of sectors here, se "4096" does not mean 4 KB but > 4096*512=2MB. > > I think you should use "-a 8", because 4k sectors = 8*512B sectors. > > -- > Olivier Smedts _ > ASCII ribbon campaign ( ) > e-mail: olivier@gid0.org - against HTML email & vCards X > www: http://www.gid0.org - against proprietary attachments / \ > > "Il y a seulement 10 sortes de gens dans le monde : > ceux qui comprennent le binaire, > et ceux qui ne le comprennent pas." >