From owner-freebsd-questions@FreeBSD.ORG Wed Dec 16 23:34:05 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E90D010656A3 for ; Wed, 16 Dec 2009 23:34:05 +0000 (UTC) (envelope-from fbsd1@a1poweruser.com) Received: from mail-03.name-services.com (mail-03.name-services.com [69.64.155.195]) by mx1.freebsd.org (Postfix) with ESMTP id D7A6D8FC08 for ; Wed, 16 Dec 2009 23:34:05 +0000 (UTC) Received: from [10.0.10.3] ([202.69.173.40]) by mail-03.name-services.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 16 Dec 2009 15:34:05 -0800 Message-ID: <4B296E66.6030405@a1poweruser.com> Date: Thu, 17 Dec 2009 07:33:58 +0800 From: Fbsd1 User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) MIME-Version: 1.0 To: FreeBSD Questions Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 16 Dec 2009 23:34:05.0273 (UTC) FILETIME=[418B3C90:01CA7EA8] X-Sender: fbsd1@a1poweruser.com Subject: is this booting info correct? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Dec 2009 23:34:06 -0000 Users with Microsoft/Windows knowledge of how a hard drive is configured may have a terminology issue with FreeBSD. Microsoft/Windows and FreeBSD use the word partition to mean different (but related) things. FreeBSD and Microsoft/Windows have primary-partitions, but they call them different things. FreeBSD calls the Microsoft/Windows primary-partition a slice. The number of hard drive primary-partitions/slices is determined by the motherboard BIOS (Basic input output system), not the operating system. Standard motherboard BIOS limits hard-drives to 4 main divisions Each of those are called primary-partitions in Microsoft/Windows terminology and slices in FreeBSD terminology. Each primary-partition/slice can be sub-divided into smaller chunks. In Microsoft/Windows, they are called extended-partitions. They are implemented very differently and are not compatible with FreeBSD. In FreeBSD the sub-divisions are called partitions. Each one of the 4 max primary-partitions/slices can be made bootable. The first physical track of the allocated space of each primary-partition/slice has an initial sector (512 byte block) that is called the boot sector. If it contains boot up code the motherboard BIOS considers it to be bootable. Each physical hard drive in the PC has it's own MBR (Master Boot Record). The MBR is located in sector-0 of the first physical track on the hard drive. The standard MBR in Microsoft/Windows and FreeBSD defaults to booting the first primary-partition/slice allocated on the first hard drive cabled to the PC. There are MBR booting programs that you can load into the MBR on the first physical cabled hard drive to scan for other bootable primary-partitions/slices on this hard drive and any other hard drives cabled to the PC. It displays a menu giving you the option to choose which one you want to boot from. This gives you the ability to have more that one operating system installed on your PC at one time.