From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from srv2.trombetti.net ([65.254.53.252]:4563 "EHLO srv2.trombetti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759122Ab2LIWvZ (ORCPT ); Sun, 9 Dec 2012 17:51:25 -0500 Message-ID: <50C515F8.6020801@shiftmail.org> Date: Sun, 09 Dec 2012 23:51:36 +0100 From: Bob Marley MIME-Version: 1.0 To: Hugo Mills , =?ISO-8859-1?Q?Sw=E2mi_Petaramesh?= , Linux Btrfs Subject: Re: BTRFS, getting darn slower everyday References: <50714AC8.4010100@petaramesh.org> <201210071259.05801.Martin@lichtvoll.de> <50718C44.2080701@petaramesh.org> <201210071648.54027.Martin@lichtvoll.de> <20121209164125.1bd91f23@natsu> <50C4740E.1060906@petaramesh.org> <20121209113824.GE14469@carfax.org.uk> In-Reply-To: <20121209113824.GE14469@carfax.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 12/09/12 12:38, Hugo Mills wrote: > On Sun, Dec 09, 2012 at 12:20:46PM +0100, Swâmi Petaramesh wrote: >> Le 09/12/2012 11:41, Roman Mamedov a écrit : >>> CoW filesystem incurs fragmentation by its nature, not specifically snapshots. >>> Even without snapshots, rewriting portions of existing files will write the >>> new blocks not over the original ones, but elsewhere, thus increasing >>> fragmentation. >> Is it to expect that somewhere in the future, BTRFS will be able to >> defragment itself without duplicating snapshot data ? > In the presence of snapshots that are modified, no, it's impossible > to fully defrag all the files. Of course, but I would agree with the poster that it would be important to "partially" defrag all the files, avoiding at least unneeded fragmentation... At least the fragmentation generated by normal writes