From owner-freebsd-hackers@freebsd.org Mon Aug 31 06:53:11 2015 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7C00C9C4C0A for ; Mon, 31 Aug 2015 06:53:11 +0000 (UTC) (envelope-from dieterbsd@gmail.com) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 614FC14A3 for ; Mon, 31 Aug 2015 06:53:11 +0000 (UTC) (envelope-from dieterbsd@gmail.com) Received: by mailman.ysv.freebsd.org (Postfix) id 5E4609C4C09; Mon, 31 Aug 2015 06:53:11 +0000 (UTC) Delivered-To: hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5DDAE9C4C07 for ; Mon, 31 Aug 2015 06:53:11 +0000 (UTC) (envelope-from dieterbsd@gmail.com) Received: from mail-ig0-x234.google.com (mail-ig0-x234.google.com [IPv6:2607:f8b0:4001:c05::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 2F47A14A2 for ; Mon, 31 Aug 2015 06:53:11 +0000 (UTC) (envelope-from dieterbsd@gmail.com) Received: by igboj15 with SMTP id oj15so18518052igb.1 for ; Sun, 30 Aug 2015 23:53:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=BuUymr7A0gGdMjMj+zL3DWFeQ/tIK+bL/oAx+MARoUU=; b=MUhCFrXmGaDgB2+/vkGxxL1C1lfFJVCVbAYY/AoMMvCZOjEwysZD1yIaqw1OI4p1eP BTALNWBvL5ZhFPiwG/eOTPFJe6WbUaqKSSH8DvMCokoWWpvHR9kjh89kBGEg9DyJYhxf Eom4OI9S7cWPj9+KfnUuw9C0XqPzUiZvBf33vh0KR9dNn97JLBSwI3VqE/wvhlQa6Wsz rL6prbyNkRXr9QEFZoirrofUbw2E2cJEnGrjo6vHdPHttcvj8Y1iGyepV7MX7q6yzSnV kmBmrcCiAaJZJhKO69st20BAff5j4ZDX31t/WKoZYFw2aps0M0BBc9mX1qbZKv1kMoF2 gYXA== MIME-Version: 1.0 X-Received: by 10.50.66.197 with SMTP id h5mr12033228igt.82.1441003990557; Sun, 30 Aug 2015 23:53:10 -0700 (PDT) Received: by 10.64.2.132 with HTTP; Sun, 30 Aug 2015 23:53:10 -0700 (PDT) Date: Sun, 30 Aug 2015 23:53:10 -0700 Message-ID: Subject: Re: Puzzle involving serial console and ...??!? From: Dieter BSD To: hackers@freebsd.org Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 31 Aug 2015 06:53:11 -0000 > I have determined that whether or not I have a functioning serial > console for freebeast depends on whether I boot albert from slice > 1 or slice 2: if from slice 1, it doesn't work; if from slice 2, > it does. > > Even when the contents of the 2 slices are functionally equivalent > (that is, the file systems of the 2 slices are as "the same" as a > "dump 0Lf | restore" pipeline can make them, except for a deliberate > difference in the contents of /etc/fstab (as the root and /usr file > systems are on different slices in the two cases)). You could verify that the 2 slices are *really* the same with find(1) and cmp(1). (both root and /usr) You could compare the boot messages in /var/log to see if there are any differences. Are there any pesky error messages on the console or in /var/log? You could try cu(1) instead of tip and see if the same thing happens. When it doesn't work, what, exactly, happens differently? Obviously, albert has an intermittent connection, and booting from a different part of the disk causes different vibrations, which causes the connection to either short or open. What's that? SSD? Never mind. :-)