From owner-freebsd-fs@FreeBSD.ORG Mon Nov 17 12:05:59 2014 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 92232C4 for ; Mon, 17 Nov 2014 12:05:59 +0000 (UTC) Received: from cu01176a.smtpx.saremail.com (cu01176a.smtpx.saremail.com [195.16.150.151]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 52325B67 for ; Mon, 17 Nov 2014 12:05:58 +0000 (UTC) Received: from [172.16.2.2] (izaro.sarenet.es [192.148.167.11]) by proxypop03.sare.net (Postfix) with ESMTPSA id 0C14E9DCAC9 for ; Mon, 17 Nov 2014 12:58:51 +0100 (CET) From: Borja Marcos Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Subject: BIOS booting from disks > 2TB Date: Mon, 17 Nov 2014 12:58:48 +0100 Message-Id: <9A929629-2EA9-47FB-A8A8-1874BB0283A5@sarenet.es> To: "freebsd-fs@FreeBSD.org Filesystems" Mime-Version: 1.0 (Apple Message framework v1283) X-Mailer: Apple Mail (2.1283) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 17 Nov 2014 12:05:59 -0000 Hi I've been trying to install FreeBSD on a 3TB disk attached to a Proliant = Microserver G8. The system is unable to boot, complaining about an error with the GPT backup table. = I don't have the machine here now, but I can reproduce this evening if someone really needs to see the = actual messages. The machine doesn't have UEFI, it can just boot via BIOS, and I = understand that the reading of the backup table is failing because the BIOS can just use 32 bits to specify a sector = number. Would it be possible to "fix" the boot process so that, if the following = conditions apply, that check is omitted? - Boot using BIOS, not UEFI - bits(disk size) > 32 What would be the side effects? Of course we can't assume it will be = safe to boot from a ZFS pool with devices larger than 2TB, as there is no guarantee that all the blocks it = needs to read are within the 2 TB limit.=20 But it should be safe to, at least, boot from a UFS partition contained = below the 2 TB limit. Any thoughts? Borja.