From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1QndbL-000347-I9 for garchives@archives.gentoo.org; Sun, 31 Jul 2011 21:31:11 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 1607E21C0A2; Sun, 31 Jul 2011 21:30:56 +0000 (UTC) Received: from mail-fx0-f53.google.com (mail-fx0-f53.google.com [209.85.161.53]) by pigeon.gentoo.org (Postfix) with ESMTP id A9BA821C063 for ; Sun, 31 Jul 2011 21:29:45 +0000 (UTC) Received: by fxd23 with SMTP id 23so5684498fxd.40 for ; Sun, 31 Jul 2011 14:29:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=YbwDobmcr5TqxbQdwVJNwhRLP/IwiX/P4uvJgC+2SDU=; b=m7en0lFI6UZzyBNwtlryL1P4fwGr5Pf4I1yVUDLGd/8yPYtkshSS9vtPJtU1fzxqvt 0qiYafeXaPwXbt8PziMV8jeZCSwjDzTPWkfTMibvcG9zu2KLA6PuxFpFBXo05KR2ONVY skaGufdxX9wznKMNqU4eLKclHfQnfo3dRsxSA= Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.223.159.8 with SMTP id h8mr5362869fax.3.1312147784739; Sun, 31 Jul 2011 14:29:44 -0700 (PDT) Received: by 10.223.28.139 with HTTP; Sun, 31 Jul 2011 14:29:44 -0700 (PDT) In-Reply-To: <201107311839.21845.peter@humphrey.ukfsn.org> References: <201107311650.29138.peter@humphrey.ukfsn.org> <201107311839.21845.peter@humphrey.ukfsn.org> Date: Sun, 31 Jul 2011 17:29:44 -0400 Message-ID: Subject: Re: [gentoo-user] jbd2 keeps spinning my disk up From: Michael Mol To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 X-Archives-Salt: X-Archives-Hash: 6e382d4ec4e5cdf62816382d1c36230f On Sun, Jul 31, 2011 at 1:39 PM, Peter Humphrey wrote: > On Sunday 31 July 2011 17:05:39 Michael Mol wrote: > >> However, if it's doing that, then it probably has something it needs to >> write to disk. That might be metadata updates. > > What, at least once a minute? While the system's idling, waiting for > something to do? Doesn't sound likely to me. > >> Have you tried adding things to your mount parameters like 'noatime' or >> 'relatime'? > > I've been specifying 'noatime' on all partitions for several years now; it's > automatic behaviour on my part. > >> What about "data=writeback"? > > I don't like the sound of the warning in the man page. > > Thanks for the ideas. So far I'm inclining to the reformatting I mentioned. Here's what I think is happening: ext3/ext4 is not going to arbitrarily poll writes to disk without there being something to write. Some program, somewhere on your system is doing something that involves modifying a file. Any filesystem that provides guarantees about disk integrity is going to get that data to a physically persistent state ASAP. That's why we have journaled filesystems in the first place: to speed that up. So, with the same application and configuration set, you're going to see the same behavior on any filesystem which provides such guarantees. You're perfectly welcome to reformat if you're so inclined; it really sounds like you're simply more comfortable (or more interested in) reiserfs. If you perceive that that solve your problem, great--but I don't think that would really solve the underlying technical issue. What you really want to do is find some way to log what's actually driving the data writes. If it were a particular app, it'd be as simple as launching the app via strace and analyzing the output. I don't know how one would do that system-wide, though. Perhaps someone else might have ideas. -- :wq