From owner-freebsd-stable@FreeBSD.ORG Wed Jun 8 19:21:12 2011 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B90D4106564A for ; Wed, 8 Jun 2011 19:21:12 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 0AAB68FC08 for ; Wed, 8 Jun 2011 19:21:11 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id WAA24666; Wed, 08 Jun 2011 22:21:08 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1QUOJQ-000IOI-Dm; Wed, 08 Jun 2011 22:21:08 +0300 Message-ID: <4DEFCBA2.10908@FreeBSD.org> Date: Wed, 08 Jun 2011 22:21:06 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.17) Gecko/20110503 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: Jeremy Chadwick References: <4DEF7322.8030907@gmx.de> <4DEF8103.9030401@gmx.de> <20110608162626.GA94883@icarus.home.lan> <4DEFA5E3.8080806@FreeBSD.org> <20110608165515.GA95345@icarus.home.lan> In-Reply-To: <20110608165515.GA95345@icarus.home.lan> X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-stable@FreeBSD.org Subject: Re: [SOLVED] Re: labelling root file system (RELENG_8) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Jun 2011 19:21:12 -0000 on 08/06/2011 19:55 Jeremy Chadwick said the following: > On Wed, Jun 08, 2011 at 07:40:03PM +0300, Andriy Gapon wrote: >> on 08/06/2011 19:26 Jeremy Chadwick said the following: >>> I have the exact same question except not with regards to labels but >>> toggling TRIM capability on the root filesystem. >>> >>> - Start system >>> - At loader, boot single-user (option 4) >>> - At prompt choose /bin/sh >>> - mount -a >> >> I think that this is a culprit. > > I'll try removing this step. > >>> - tunefs -t enable /dev/ada0s1a --- fails >> >> Shouldn't you have / mounted r/o here? >> BTW, AFAIR, *re*-mounting root read-only won't help; it needs to have never been >> mounted r/w. > > I'm a little confused by this sentence, so my apologise in advance. / > is mounted read-only in single-user by default. Did you mean I should > make it r/w by doing "mount -u -o rw /" ? I may have omitted this step. No. My English is not perfect it seems - my point was that you should never mount your root fs r/w if you want to do tunefs on it. > I will re-verify the exact procedure and exact steps in a moment, and > reply here. > >>> - sysctl kern.geom.debugflags=16 >>> - tunefs -t enable /dev/ada0s1a --- works >>> - tunefs -p /dev/ada0s1a -- shows TRIM enabled >>> - reboot >> >> I think that at this step your superblock on disk gets re-written with its copy in >> memory which has never been updated. But not sure. > > Hmm, I sure hope that isn't the case. I think that this is the case. > That would mean the only time a > person can use tunefs on a root filesystem is when they either do it > manually during the FreeBSD installation (adding "-t" to the list of > newfs flags in the filesystem creation UI), or if they boot off of some > other medium (USB flash drive, CD, PXE, etc.). Or when your root fs is mounted r/o, which is not as bad as what you listed above. -- Andriy Gapon