From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 16 Jan 2001 16:19:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 16 Jan 2001 16:19:16 -0500 Received: from [24.65.192.120] ([24.65.192.120]:21752 "EHLO webber.adilger.net") by vger.kernel.org with ESMTP id ; Tue, 16 Jan 2001 16:18:57 -0500 From: Andreas Dilger Message-Id: <200101162118.f0GLIRL14159@webber.adilger.net> Subject: Re: Linux not adhering to BIOS Drive boot order? In-Reply-To: "from Dr. Kelsey Hudson at Jan 16, 2001 12:30:34 pm" To: "Dr. Kelsey Hudson" Date: Tue, 16 Jan 2001 14:18:26 -0700 (MST) CC: Venkatesh Ramamurthy , "'linux-scsi@vger.kernel.org'" , "'linux-kernel@vger.kernel.org'" X-Mailer: ELM [version 2.4ME+ PL73 (25)] MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Kelsey Hudson writes: > however, this brings up an interesting question: what happens if two disks > (presumably from two different machines) have the same disk label? what > happens then? for instance, i have several linux machines both at my > workplace and my home. if for some reason one of these machines dies due > to hardware failure and i want to get stuff off the drives, i put the disk > containing the /home partition on the failed machine into a working > machine and reboot. What /home gets mounted then? the original /home or > the new one from the dead machine? (and don't say end users wouldn't > possibly do that... if they are adding hardware into their systems this is > by no means beyond their capabilities) Don't do that (tm). You may still have that problem (or even all filesystems being mounted wrong) if you add a new drive to a SCSI chain. Likewise if you add an IDE controller, the controllers may be numbered differently... > at least with physical device nodes i can say 'computer, you will mount > this partition on this mountpoint!' and be done with it. If you use a UUID, you will never have conflicts (unless you do drive imaging, which is bad). The label is just a lot more convenient to use than the UUID. > so tell me then, how would one discern between two partitions with the > same label? It will pick the first one found, I guess. However, this still reduces the problem of drive renaming by 99%. It goes from "each time drives are added/moved/removed my system may be broken" to "if I insert two drives with the same label 50% chance my system is broken". I'll take the latter any day. Cheers, Andreas -- Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto, \ would they cancel out, leaving him still hungry?" http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/