From: Greg Freemyer Subject: Re: [PATCH 00/11 RESEND] e4defrag: fragmentation score rework and cleanups Date: Fri, 17 Jun 2011 09:08:19 -0400 Message-ID: References: <4DF916B8.5010001@wpkg.org> <4DF99052.8020201@sx.jp.nec.com> <4DF9BC52.40203@wpkg.org> <4DFAE285.9010503@sx.jp.nec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Tomasz Chmielewski , linux-ext4@vger.kernel.org To: Kazuya Mio Return-path: Received: from mail-bw0-f46.google.com ([209.85.214.46]:37291 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753743Ab1FQNIv (ORCPT ); Fri, 17 Jun 2011 09:08:51 -0400 Received: by bwz15 with SMTP id 15so747213bwz.19 for ; Fri, 17 Jun 2011 06:08:49 -0700 (PDT) In-Reply-To: <4DFAE285.9010503@sx.jp.nec.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Jun 17, 2011 at 1:13 AM, Kazuya Mio wrote: > 2011/06/16 17:18, Tomasz Chmielewski wrote: >> >> I noticed that when using e4defrag on such a file-based image, while the >> guest is running (i.e. the file is in use), all IO from that guest to >> the disk (disk is this file) is "frozen". >> >> In other words, as soon as we run e4defrag, any guest writes to that >> file will only complete if e4defrag finishes. As the images can be quite >> big, it can mean guest IO can be frozen even for hours. >> >> >> Is it a known/intended limitation (at least, it behaved like this when I >> tried e4defrag a few months ago)? > > Thank you for the feedback. I will try to reproduce this problem later. > > Regards, > Kazuya Mio Kazuya, When trying to come up with a better plan for handling large files, you may want to review this msg and Akira's response from last spring: http://www.kerneltrap.com/mailarchive/linux-ext4/2010/3/30/6899823 Greg