From: "Takashi Sato" Subject: Re: ext2/3/4 online defrag Date: Thu, 10 May 2007 18:20:55 +0900 Message-ID: <020201c792e4$86569b10$4168010a@bsd.tnes.nec.co.jp> References: <1178770799.26695.11.camel@eric-laptop> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-2022-jp"; reply-type=original Content-Transfer-Encoding: 7bit Cc: To: "Eric" Return-path: Received: from TYO200.gate.nec.co.jp ([210.143.35.50]:56871 "EHLO tyo200.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757328AbXEJJZQ (ORCPT ); Thu, 10 May 2007 05:25:16 -0400 Received: from tyo202.gate.nec.co.jp ([10.7.69.202]) by tyo200.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id l4A9PEuM000658 for ; Thu, 10 May 2007 18:25:14 +0900 (JST) Received: from mailgate3.nec.co.jp (mailgate54.nec.co.jp [10.7.69.197]) by tyo202.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id l4A9LCx6002493 for ; Thu, 10 May 2007 18:21:12 +0900 (JST) Received: (from root@localhost) by mailgate3.nec.co.jp (8.11.7/3.7W-MAILGATE-NEC) id l4A9LCC08641 for linux-ext4@vger.kernel.org; Thu, 10 May 2007 18:21:12 +0900 (JST) Received: from secsv3.tnes.nec.co.jp (tnesvc2.tnes.nec.co.jp [10.1.101.15]) by mailsv.nec.co.jp (8.11.7/3.7W-MAILSV-NEC) with ESMTP id l4A9LCO23579 for ; Thu, 10 May 2007 18:21:12 +0900 (JST) Received: from tnesvc2.tnes.nec.co.jp ([10.1.101.15]) by secsv3.tnes.nec.co.jp (ExpressMail 5.10) with SMTP id 20070510.182116.81202716 for ; Thu, 10 May 2007 18:21:16 +0900 Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hi, > I've searched the archives and googled around, and I've come to the > following conclusions: > *An offline defrag tool is available but dangerous. > *Some patches exist that provide preliminary support for online defrag > in the ext3 driver, but interest in improving/integrating these patches > is low. > *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. I'm working on the development of online defrag for ext4. The defrag can work effectively for fragmented huge files. So I'm focussing on ext4 which can store many huge files and developing the defrag for extent files on ext4. Any comments are very welcome. Takashi