From: Eric Sandeen Subject: Re: [patch] ext2/3: document conditions when reliable operation is possible Date: Wed, 26 Aug 2009 23:28:04 -0700 Message-ID: <4A962774.9000604@redhat.com> References: <20090824212518.GF29763@elf.ucw.cz> <20090824223915.GI17684@mit.edu> <20090824230036.GK29763@elf.ucw.cz> <4A932B18.1020209@redhat.com> <20090825093414.GB15563@elf.ucw.cz> <4A94ACDF.30405@redhat.com> <20090826111751.GC26595@elf.ucw.cz> <20090826131028.GB1370@ucw.cz> <20090826180248.GB6997@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: Theodore Tso , david@lang.hm, Pavel Machek , Rik van Riel , Ric Wheeler , Florian Weimer , Goswin v Return-path: Received: from sandeen.net ([209.173.210.139]:27337 "EHLO mail.sandeen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751002AbZH0G2H (ORCPT ); Thu, 27 Aug 2009 02:28:07 -0400 In-Reply-To: <20090826180248.GB6997@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: Theodore Tso wrote: > On Wed, Aug 26, 2009 at 06:43:24AM -0700, david@lang.hm wrote: >>>> as the ext3 authors have stated many times over the years, you still need >>>> to run fsck periodicly anyway. >>> Where is that documented? >> linux-kernel mailing list archives. > > Probably from some 6-8 years ago, in e-mail postings that I made. My > argument has always been that PC-class hardware is crap, and it's a > Really Good Idea to periodically check the metadata because corruption > there can end up causing massive data loss. The main problem is that > doing it at reboot time really hurt system availability, and "after 20 > reboots (plus or minus)" resulted in fsck checks at wildly varying > intervals depending on how often people reboot. Aside ... can we default mkfs.ext3 to not set a mandatory fsck interval then? :) -Eric > What I've been recommending for some time is that people use LVM, and > run fsck on a snapshot every week or two, at some convenient time when > the system load is at a minimum. There is an e2croncheck script in > the e2fsprogs sources, in the contrib directory; it's short enough > that I'll attach here here. > > Is it *necessary*? In a world where hardware is perfect, no. In a > world where people don't bother buying ECC memory because it's 10% > more expensive, and PC builders use the cheapest possible parts --- I > think it's a really good idea. > > - Ted