From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: util-linux-owner@vger.kernel.org Received: from quantum.linuxfromscratch.org ([216.171.237.234]:35633 "EHLO quantum.linuxfromscratch.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759938Ab2J3XKj (ORCPT ); Tue, 30 Oct 2012 19:10:39 -0400 Received: from [192.168.0.3] (5ad2953d.bb.sky.com [90.210.149.61]) by quantum.linuxfromscratch.org (Postfix) with ESMTPA id 5B6AD14182 for ; Tue, 30 Oct 2012 17:04:00 -0600 (MDT) Message-ID: <1351638239.1651.13.camel@kyoto.localdomain> Subject: Discrepancies between real and symlinked mtab From: Matt Burgess To: util-linux@vger.kernel.org Date: Tue, 30 Oct 2012 23:03:59 +0000 Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: util-linux-owner@vger.kernel.org List-ID: Hi, Consider trying to answer the question "What partition is mounted on /" (it happens to be /dev/sda3 in this example), when /etc/mtab is a symlink pointing to /proc/mounts: 1) mount(8) /dev/root on / type ext3 (rw,relatime,data=ordered) Nope, that's not /dev/sda3. And what is /dev/root anyway? There's no such node under /dev here. 2) df(1) Filesystem 1K-blocks Used Available Use% Mounted on rootfs 20642428 1576788 18017064 9% / /dev/root 20642428 1576788 18017064 9% / Uh-oh - now I appear to have 2 filesystems mounted at '/' (yes, I know you can tell by the same stats that it is in fact the same FS). What is this rootfs entry? 3) lsblk(8) NAME FSTYPE LABEL UUID MOUNTPOINT sda3 ext3 /lfs aaf09e8b-d50e-429e-ba8e-11fa07ab5b75 Well, that's odd. I know that /dev/sda3 is mounted at /, but apparently lsblk(8) doesn't! If /etc/mtab is a real file, then the output of all 3 commands is correct (and by that I mean it shows /dev/sda3). As all 3 utils show the same issue, I assume this is something to do with libblkid? Thanks, Matt.