From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher Chan Subject: Re: Which version will be merged into mainline kernel? Date: Tue, 14 Nov 2006 14:01:32 +0800 Message-ID: <45595BBC.6000602@netvigator.com> References: <194f62550610160250u265ef120lee3cf9a17266939f@mail.gmail.com> <454A596F.8070909@namesys.com> <194f62550611072321j1cd34205u55f3c121dcac7aac@mail.gmail.com> <200611081015.14320.biscani@pd.astro.it> <20061108102136.GS6012@schatzie.adilger.int> <4557E254.5060404@netvigator.com> <45582353.3070709@slaphack.com> <45583C43.5070904@netvigator.com> <45589ECD.4070105@slaphack.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <45589ECD.4070105@slaphack.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: David Masover Cc: reiserfs-list@namesys.com >> Which is why data important software use fsync/fsyncdata to minimize >> data loss from crashes. > > If (and only if) you actually read and accepted the paragraph you're > quoting there, the point is that using fsync and fdatasync on these is > kind of like doing bad block relocation in software, when the hard disk > is already doing it for you. There are situations where it's useful, but > mostly, it's just a performance drain without a point. You have no idea what fsync/fsyncdata does. They cannot be compared to bad block relocation at all. That is an apples to oranges comparison. > > I don't necessarily agree with this point of view, but there you go. > >>> could probably argue the other side just as effectively. Besides, at >>> least on my experimental/gaming rig, I like a little adrenaline in my >>> admin work! >>> >> >> Try arguing why you lost thousands of mails when the box crashed and >> justifying it. > > There aren't thousands of mails on my experimental dev/gaming rig. Also, > it hasn't crashed in a month or two (I seem to have upgraded/hacked my > way out of its last major crasher), and it's running all kinds of > experimental stuff. Sure, individual programs crash from time to time > (especially my hacks), but that's irrelevant to the fsync discussion. I was not referring to your gaming rig. Did you say that you don't use fsync for your production boxes? > So, as far as I can tell, this mailserver (that I'm sending this from > right now), which is amd64/reiser4/no_fsync, hasn't lost a single > message. And I don't even have an APM on it (although that reminds me, I > need to buy one now, as in, "tomorrow" now.) Heh. Just wait till you get a crash shortly after a write with fsync disabled. > > Anyway, are we done here? I don't think I disagree with your points, > maybe just your absolutism. Ha! Got tell that to a bank or any body who uses a database to store important data. Hans knows what he is doing providing data guarantee with fsync. I was very surprised when I heard all those reports about zero data loss on reiser4 boxes after a crash. Now I have an idea why.