From: Jan Kara Subject: Re: ext2/3/4 online defrag Date: Thu, 17 May 2007 18:11:19 +0200 Message-ID: <20070517161119.GB3230@atrey.karlin.mff.cuni.cz> References: <1178770799.26695.11.camel@eric-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Eric Return-path: Received: from atrey.karlin.mff.cuni.cz ([195.113.31.123]:43447 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755370AbXEQQLU (ORCPT ); Thu, 17 May 2007 12:11:20 -0400 Content-Disposition: inline In-Reply-To: <1178770799.26695.11.camel@eric-laptop> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hello, Sorry for replying a bit late... > This is my first post to the list. I want to add online defrag support > to ext2/3/4 just to scratch an itch. > > I've searched the archives and googled around, and I've come to the > following conclusions: > *An offline defrag tool is available but dangerous. For original e2defrag - yes. But me (and several other people independently as I've learnt recently) have written some tools which should result in something useful. If you're interested, you can join prefetch-devel@googlegroups.com - it's led by one guy who is doing defrag and stuff as his google summer of code project. > *Some patches exist that provide preliminary support for online defrag > in the ext3 driver, but interest in improving/integrating these patches > is low. The code itself for ext3 is not a big deal. Main problem are kernel interfaces and I hope to find some time soon to put together some reasonable proposal for reasonably generic calls... > *An implementation of an ext* filesystem driver can work with any > ext2/3/4 filesystem as long as it supports the necessary revision > (GOOD_OLD_REV or DYNAMIC_REV) and feature flags set in the filesystem. Not sure what you mean here... Honza -- Jan Kara SuSE CR Labs