Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752801AbZADOY4 (ORCPT ); Sun, 4 Jan 2009 09:24:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750909AbZADOYr (ORCPT ); Sun, 4 Jan 2009 09:24:47 -0500 Received: from ey-out-2122.google.com ([74.125.78.27]:14090 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750696AbZADOYq (ORCPT ); Sun, 4 Jan 2009 09:24:46 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=Ujz49SxU6+jBIwWN03DFCS9GeiVdFHZ+N8bNAun6z4YPpU4KrYj48tvOHRSvYNoys0 6PlxncdorwXpl6DRVG68fuB+Hcu+ktf3bPbRjwfuNgSfySUhO086/PvS89JaCzOQMao4 lSHVfM+JnH7iMfXgrHFSy5bUqKWyJarE/n/AM= Message-ID: Date: Sun, 4 Jan 2009 14:24:43 +0000 From: "Duane Griffin" To: Valdis.Kletnieks@vt.edu Subject: Re: document ext3 requirements Cc: "=?WINDOWS-1252?Q?Martin_MOKREJ=8A?=" , "Pavel Machek" , "kernel list" , "Andrew Morton" , tytso@mit.edu, mtk.manpages@gmail.com, rdunlap@xenotime.net, linux-doc@vger.kernel.org In-Reply-To: <15786.1231041158@turing-police.cc.vt.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20090103123813.GA1512@ucw.cz> <20090103222957.GG1666@elf.ucw.cz> <495FEE66.9080903@ribosome.natur.cuni.cz> <495FF9CE.2020908@ribosome.natur.cuni.cz> <495FFECB.5040001@ribosome.natur.cuni.cz> <15786.1231041158@turing-police.cc.vt.edu> X-Google-Sender-Auth: 25b6d5a2effcafbf Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1449 Lines: 31 2009/1/4 : > On Sun, 04 Jan 2009 00:41:51 GMT, Duane Griffin said: > >> I agree, it isn't a great situation. Nonetheless, it has always been >> thus for ext3, and so far we've muddled along. Unless and until we can >> replay the journal in-memory without touching the on-disk data, we are >> stuck with it. > > Is there a way using md/dm/lvm etc to make the source partition R/O and > replay the journal onto a CoW snapshop? Admittedly, not easy to do inside > the 'mount' command itself, but at least it might be workable for LiveCD R/O > mounts and forensics work, where you can *tell* beforehand that's what you > want and can jump through setup games before doing the mount... Yes, something like that is best practice, as I understand it. The LiveCD init scripts could check whether they are about to R/O mount an ext[34] filesystem needing recovery and either refuse with a useful message to the user, or even automatically create and mount a COW snapshot, as you described. They'd still need to warn the user though, since things like remounting R/W wouldn't work as expected. Cheers, Duane. -- "I never could learn to drink that blood and call it wine" - Bob Dylan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/