From mboxrd@z Thu Jan 1 00:00:00 1970 From: Redeeman Subject: Re: Desktop Filesystem Benchmarks in 2.6.3 Date: Sun, 07 Mar 2004 13:15:54 +0100 Message-ID: <1078661754.5798.0.camel@redeeman.linux.dk> References: <4044119D.6050502@andrew.cmu.edu> <4044366B.3000405@namesys.com> <4044B787.7080301@andrew.cmu.edu> <20040303234104.GD1875@convergence.de> <20040305184643.GA4758@openzaurus.ucw.cz> <1078586701.6237.0.camel@redeeman.linux.dk> Reply-To: redeeman@metanurb.dk Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <1078586701.6237.0.camel@redeeman.linux.dk> List-Id: Content-Type: text/plain; charset="us-ascii" To: Reiserfs Mailinglist On Fri, 2004-03-05 at 19:46, Pavel Machek wrote: > Hi! > > > It would be nice if someone with more profound knowledge could comment > > on this, but my understanding of the problem is: > > > > - journaled filesystems can only work when they can enforce that > > journal data is written to the platters at specifc times wrt > > normal data writes > > - IDE write caching makes the disk "lie" to the kernel, i.e. it says > > "I've written the data" when it was only put in the cache > > - now if a *power failure* keeps the disk from writing the cache > > contents to the platter, the fs and journal are inconsistent > > (a kernel crash would not cause this problem because the disk can > > still write the cache contents to the platters) > > - at next mount time the fs will read the journal from the disk > > and try to use it to bring the fs into a consistent state; > > however, since the journal on disk is not guaranteed to be up to date > > this can *fail* (I have no idea what various fs implementations do > > to handle this; I suspect they at least refuse to mount and require > > you to manually run fsck. Or they don't notice and let you work > > with a corrupt filesystem until they blow up.) > > > > Right? Or is this just paranoia? > > Twice a year I fsck my reiser drives, and yes there's some corruption there. > So you are right, and its not paranoia. AAAAARRRRRRGGGGHHHHHH!!! i have a reiserfs partition with my maildir, i have often lost power, but i havent fscked, will that mean great chances that i have lost something?? -- Regards, Redeeman () ascii ribbon campaign - against html e-mail /\ - against microsoft attachments