From owner-freebsd-questions@freebsd.org Sun Mar 27 15:18:53 2016 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C1315ADF183 for ; Sun, 27 Mar 2016 15:18:53 +0000 (UTC) (envelope-from brandon.wandersee@gmail.com) Received: from mail-io0-f178.google.com (mail-io0-f178.google.com [209.85.223.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 9896A146B for ; Sun, 27 Mar 2016 15:18:53 +0000 (UTC) (envelope-from brandon.wandersee@gmail.com) Received: by mail-io0-f178.google.com with SMTP id e3so41423761ioa.1 for ; Sun, 27 Mar 2016 08:18:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:date:message-id:mime-version; bh=X7b6Lm2Pi/V5ciYDhoD/gfsgmkFa1/4aC5Hbx7Lgz7k=; b=gOC4S/iBbS7kM1E0OYSIWnq36lMB+wIu1UQ8chiYtlaJusmKxo/FNd2oVq52VBt+SK U+iYgDfKmaH05uYJfDM0yazKpjBz2m8K5I70qvXgEuRGGo19ZStKr79SJ3Cxe8OK+VzA 8kOkRjIfQ+Qdmkg7Cikvu59FHQ4XhHVDL3UKsVZkn+EEl8eGAnGaYGK6flF7tLhd4gYl eDxgTFkvetD5jrqcJ9C0ta86AFm2PZajc6kmS3LJ+SP82oNRzIjUl3EXgAedgtT39IGj 0UYPGa404yLNlS725aTbISkWfsSp8MHgAjbUI88ZnVIv13YE1DitwTu3XvffzJln0uZA Fyfg== X-Gm-Message-State: AD7BkJJtlhWkD7yLD140P53VxIHiL53Sluo05BGnV3GnobVK1qXNlZnbt8HLDA7v14q1vA== X-Received: by 10.107.157.70 with SMTP id g67mr20388892ioe.38.1459091539991; Sun, 27 Mar 2016 08:12:19 -0700 (PDT) Received: from WorkBox.Home.gmail.com (63-231-133-17.mpls.qwest.net. [63.231.133.17]) by smtp.gmail.com with ESMTPSA id me7sm2385511igb.12.2016.03.27.08.12.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 27 Mar 2016 08:12:18 -0700 (PDT) References: User-agent: mu4e 0.9.16; emacs 24.5.1 From: Brandon J. Wandersee To: Teng Zhang Cc: freebsd-questions@freebsd.org Subject: Re: bootable freebsd slice's limit In-reply-to: Date: Sun, 27 Mar 2016 10:12:33 -0500 Message-ID: <86h9fsnee6.fsf@WorkBox.Home> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 27 Mar 2016 15:18:53 -0000 Teng Zhang writes: > In man fdisk(8), it refers to > "Note that bootable FreeBSD slices (the ``*/*'' file system) must lie > completely within the first 1024 cylinders; if this is not true, booting > may fail." > my confusion is whether this limit is aimed at just i386 platform > or all platforms that freebsd supports. Could you please tell me the actual > condition ? Hopefully someone will correct me if I'm wrong, but I don't believe the limitation is related to machine architecture. Rather, it has to do with how the legacy bootloader handles older disks with a 512k sector size and an MBR partition table. I would guess that you are asking out of concern for on-disk filesystem alignment? Is there any particular reason you cannot use GPT via gpart(8), rather than MBR via fdisk(8)? -- :: Brandon J. Wandersee :: brandon.wandersee@gmail.com :: -------------------------------------------------- :: 'The best design is as little design as possible.' :: --- Dieter Rams ----------------------------------