From owner-freebsd-questions Sun Aug 11 14: 3:28 2002 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 1764137B400 for ; Sun, 11 Aug 2002 14:03:26 -0700 (PDT) Received: from postal1.es.net (postal1.es.net [198.128.3.205]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6C22843E70 for ; Sun, 11 Aug 2002 14:03:25 -0700 (PDT) (envelope-from oberman@es.net) Received: from ptavv.es.net ([198.128.4.29]) by postal1.es.net (Postal Node 1) with ESMTP id GQF37091; Sun, 11 Aug 2002 14:03:24 -0700 Received: from ptavv (localhost [127.0.0.1]) by ptavv.es.net (Postfix) with ESMTP id 1CD645D04; Sun, 11 Aug 2002 14:03:24 -0700 (PDT) To: pjklist@ekahuna.com Cc: questions@FreeBSD.ORG Subject: Re: Fixit CD paradox: making device nodes In-reply-to: Your message of "Sun, 11 Aug 2002 02:00:26 PDT." <20020811090027768.AAA344@empty1.ekahuna.com@dyn205.ekahuna.com> Date: Sun, 11 Aug 2002 14:03:24 -0700 From: "Kevin Oberman" Message-Id: <20020811210324.1CD645D04@ptavv.es.net> Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > From: "Philip J. Koenig" > Date: Sun, 11 Aug 2002 02:00:26 -0700 > > > On 10 Aug 2002 at 18:12, Kevin Oberman boldly uttered: > > > > From: "Philip J. Koenig" > > > Date: Sat, 10 Aug 2002 10:09:34 -0700 > > > Sender: owner-freebsd-questions@FreeBSD.ORG > > > > > > Every time I try to use the Fixit CD to fix a problem with a disk I > > > run into the same problem: I can't mount the disk because the device > > > nodes are missing (ie ad0s1a), but I can't create device nodes > > > because /dev or /dist/dev (when booting from the fixit CD) is read- > > > only. > > > > You can only mount the root partition on any slice under fixit. I > > thought the initial message told you about this, but I may be > > mis-remembering. > > > > # mount /dev/ad0s1 /mnt > > > > will mount the "a" partition at the /mnt point. This assumes that the > > root partition is the 'a' partition. > > > OK, so in this case is ad0s1 essentially an alias for "ad0s1a"? If > so, I didn't realize that and thanks for the tip. (I always thought > ad0s1c was the equivalent to ad0s1) It is. The magic is found in the output from disklabel. Partitions 'a' and 'c' both start at the beginning of the disk. So mounting the disk (with no partition letter) is going to mount the partition at the beginning of the disk and that is effectively 'a' (and, often uselessly, 'c'). The bottom line is that mounting the device without any letter will give access to the root partition. > What happens if one needs to mount, say, /usr? As far as I know, you can't. The theory is that you use fixit only when the system is unable to boot which only requires the root partition. Once you get root fixed, you can boot it to single user and fix something bad on another partition. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message