From owner-freebsd-questions@FreeBSD.ORG Wed Aug 31 12:13:30 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0C01016A41F for ; Wed, 31 Aug 2005 12:13:30 +0000 (GMT) (envelope-from freebsd@meijome.net) Received: from sigma.octantis.com.au (ns2.octantis.com.au [207.44.189.124]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9F47543D49 for ; Wed, 31 Aug 2005 12:13:29 +0000 (GMT) (envelope-from freebsd@meijome.net) Received: (qmail 5997 invoked from network); 31 Aug 2005 22:13:28 +1000 Received: from 203-217-79-78.dyn.iinet.net.au (HELO ?192.168.13.3?) (203.217.79.78) by sigma.octantis.com.au with (DHE-RSA-AES256-SHA encrypted) SMTP; 31 Aug 2005 22:13:28 +1000 Message-ID: <43159EE1.4080901@meijome.net> Date: Wed, 31 Aug 2005 22:13:21 +1000 From: Norberto Meijome User-Agent: Mozilla Thunderbird 1.0.6 (Windows/20050716) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Glenn Dawson References: <43155735.4050101@meijome.net> <6.2.3.4.2.20050831012652.03013490@cobalt.antimatter.net> In-Reply-To: <6.2.3.4.2.20050831012652.03013490@cobalt.antimatter.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD Questions Subject: Re: How to create *exactly* the same partitions in different disks 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, 31 Aug 2005 12:13:30 -0000 Glenn Dawson wrote: > At 12:07 AM 8/31/2005, Norberto Meijome wrote: > > fdisk wants slices to start on a head boundary, and end on a cylinder > boundary. > > if you make start evenly divisible by the number of sectors per track, > and make size+start evenly divisible by sectors*heads, fdisk won't > change any of the numbers on you. > > So, for your disk: > > start / sectors = 332775 > you have size specified as 467427240, so: > (467427240 + 20964825) / (16 * 63) = 484515.9375 > fdisk will treat that as 484515 and do: > (16 * 63 * 484515) - 20964825 = 467426295 > and use that number as the new size. Thanks for the explanation :) > > This matches ad6. It would appear that ad4 had the start and end values > explicitly set causing it to come out with different numbers. Gotcha. ad6 , ad8 and ad10 (*) , the ones I sliced by hand, follow this rule. ad4 doesn't, which is the one that got created by sysinstall on the initial setup. I told it to create a slice of 10GB. So sysinstall doenst follow the rule? Am I missing something here? I guess i can move all of ad4s1 around to ad6s1, boot off ad6, rebuild ad4s1 and move back in... right? (*) FWIW, all four drives are exactly the same, so the only difference is how the slices were done. ad4: 238475MB at ata2-master SATA150 ad6: 238475MB at ata3-master SATA150 ad8: 238475MB at ata4-master SATA150 ad10: 238475MB at ata5-master SATA150 Beto