From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B82DC433B4 for ; Thu, 29 Apr 2021 05:33:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 465106144E for ; Thu, 29 Apr 2021 05:33:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236966AbhD2Feg (ORCPT ); Thu, 29 Apr 2021 01:34:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229792AbhD2Fef (ORCPT ); Thu, 29 Apr 2021 01:34:35 -0400 Received: from smtp.gentoo.org (mail.gentoo.org [IPv6:2001:470:ea4a:1:5054:ff:fec7:86e4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E40BDC06138B for ; Wed, 28 Apr 2021 22:33:47 -0700 (PDT) Received: from vapier (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.gentoo.org (Postfix) with ESMTPS id D59F833D3CF for ; Thu, 29 Apr 2021 05:33:45 +0000 (UTC) Date: Thu, 29 Apr 2021 01:33:38 -0400 From: Mike Frysinger To: linux-ext4@vger.kernel.org Subject: e4defrag seems too optimistic Message-ID: Mail-Followup-To: linux-ext4@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org i started running e4defrag out of curiosity on some large files that i'm archiving long term. its results seem exceedingly optimistic and i have a hard time agreeing with it. am i pessimistic ? for example, i have a ~4GB archive: $ e4defrag -c ./foo.tar.xz now/best size/ext ./foo.tar.xz 39442/2 93 KB Total/best extents 39442/2 Average size per extent 93 KB Fragmentation score 34 [0-30 no problem: 31-55 a little bit fragmented: 56- needs defrag] This file (./foo.tar.xz) does not need defragmentation. Done. i have a real hard time seeing this file as barely "a little bit fragmented". shouldn't the fragmentation score be higher ? as a measure of "how fragmented is it really", if i copy the file and then delete the original, there's a noticeable delay before `rm` finishes. -mike