From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id lBJA0AUe011753 for ; Wed, 19 Dec 2007 05:00:10 -0500 Received: from anchor-post-33.mail.demon.net (anchor-post-33.mail.demon.net [194.217.242.91]) by mx3.redhat.com (8.13.1/8.13.1) with ESMTP id lBJ9xns4015667 for ; Wed, 19 Dec 2007 04:59:49 -0500 Received: from dyn-62-56-118-152.dslaccess.co.uk ([62.56.118.152] helo=amd64.lan) by anchor-post-33.mail.demon.net with esmtpa (AUTH miasmic) (Exim 4.67) id 1J4viO-000MGb-Bs for linux-lvm@redhat.com; Wed, 19 Dec 2007 09:59:48 +0000 Subject: RE: [linux-lvm] won't dual boot: 2 disks and LVM From: cs In-Reply-To: <7C6C00FDABF70949A0A5D4DD8A4DC2170474A356@CORPUSMX20A.corp.emc.com> References: <1197988092.29413.77.camel@veri.phy.umist.ac.uk> <7C6C00FDABF70949A0A5D4DD8A4DC2170474A353@CORPUSMX20A.corp.emc.com> <1198010286.6637.10.camel@amd64.local> <7C6C00FDABF70949A0A5D4DD8A4DC2170474A356@CORPUSMX20A.corp.emc.com> Date: Wed, 19 Dec 2007 09:59:28 +0000 Message-Id: <1198058368.3859.10.camel@amd64.local> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: LVM general discussion and development On Tue, 2007-12-18 at 16:52 -0500, pham_cuong@emc.com wrote: > There is a difference between changing the boot order from the BIOS vs. > [physically] removing the master HD. Here's why: > > In the former case, the BIOS boot order is at the lower-level (earlier) > and it will take effect before the boot loader exists in each drive. > Depending on your BIOS, the boot order can be fixed or priority-based > (most BIOSes support priority-based boot path). Fixed order means that > only the specified boot order is used. Priority-based boot order means > that the system will attempt the first boot path on the list, if failed, > or timed out, goes to the 2nd boot path. BIOS boot order only changes > the order of which path to boot from first. It has no control over the > designation of which drive is detected and designated as drive 0 or > drive 1. Boot.ini has this level of granularity, and more... Down to > the partition level (one below the disk level). > > The act of removing the Master HD changes the HD designation at the > hardware level, and this in turn may affect how the system boots (for > non-SCSI only). Specifically, for your case the XP's boot.ini may > designate that XP is to be booted from the first disk (connected to > PR1), first paritition, and you've physically connect this drive as a > secondary/slave (SL) drive so XP will never boot when XP's boot loader > reads the boot.ini. Upon either moving this drive to the primary (PR1) > connection, or change the boot.ini, the drive order for this drive is > changed from disk1 to disk0, so XP would see this drive and be able to > boot from it. As you can see, in this case, changing the BIOS boot > order is inconsequential. > > Regards, > > Confucius useful stuff but I'm still unsure why if I change the order in BIOS then (when I had it working a bit) it would start the XP boot sequence (and not the GRUB from master) but then hang indefinitely...