From owner-freebsd-questions@freebsd.org Sat Jun 25 12:24:00 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 6B233B807F7 for ; Sat, 25 Jun 2016 12:24:00 +0000 (UTC) (envelope-from wblock@wonkity.com) Received: from wonkity.com (wonkity.com [67.158.26.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "wonkity.com", Issuer "wonkity.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 3BC3312D8 for ; Sat, 25 Jun 2016 12:24:00 +0000 (UTC) (envelope-from wblock@wonkity.com) Received: from wonkity.com (localhost [127.0.0.1]) by wonkity.com (8.15.2/8.15.2) with ESMTPS id u5PCNucR086206 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 25 Jun 2016 06:23:56 -0600 (MDT) (envelope-from wblock@wonkity.com) Received: from localhost (wblock@localhost) by wonkity.com (8.15.2/8.15.2/Submit) with ESMTP id u5PCNufX086203; Sat, 25 Jun 2016 06:23:56 -0600 (MDT) (envelope-from wblock@wonkity.com) Date: Sat, 25 Jun 2016 06:23:55 -0600 (MDT) From: Warren Block To: Dave cc: freebsd-questions@freebsd.org Subject: Re: The other problem : AHCI unbootable In-Reply-To: <1890864.LfRUyAIFKl@amd.asgard.uk> Message-ID: References: <1890864.LfRUyAIFKl@amd.asgard.uk> User-Agent: Alpine 2.20 (BSF 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (wonkity.com [127.0.0.1]); Sat, 25 Jun 2016 06:23:56 -0600 (MDT) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 25 Jun 2016 12:24:00 -0000 On Sat, 25 Jun 2016, Dave wrote: > On Saturday 25 June 2016 04:56:39 Manish Jain wrote: >> While installing FreeBSD 10.3 amd64, I tried switching from IDE to AHCI >> in my BIOS's boot configuration. But when I do this, the installer >> installs the OS on the hard disk, and then the system is unbootable - >> the BIOS screen hangs with the message : boot record missing. >> >> Can anyone please tell me what might be the problem ? >> > Not sure exactly what you are saying your process is, but switching between AHCI and IDE without a full and clean install will cause you problems. Solution. Don't do it. This has not been a problem for me with FreeBSD. The drivers and operating system are resilient enough to detect which mode is available and just use it. AHCI is preferred, though, giving a roughly 5-15% speed improvement. > This advice applies at least to WinXP too. That tends to reboot while > the Windows logo is on screen no matter which way around you do it. ie > if you install in IDE mode it will reboot if change to AHCI mode. > Same happens if you install in AHCI mode and then try to boot in IDE > mode. I can't recall about XP, but later versions do have AHCI drivers available. If the machine is to be dual-booted, that will limit the modes available to what works with the most limited operating system. Using FreeBSD as a single operating system and running the others as VMs with VirtualBox is one way around this.