From: Robin Dong Subject: Question about writable ext4-snapshot Date: Sat, 21 Jan 2012 10:45:27 +0800 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Tao Ma , coly , Ext4 Developers List To: amir73il@gmail.com Return-path: Received: from mail-tul01m020-f174.google.com ([209.85.214.174]:49216 "EHLO mail-tul01m020-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753279Ab2AUCp1 (ORCPT ); Fri, 20 Jan 2012 21:45:27 -0500 Received: by obcva7 with SMTP id va7so1437497obc.19 for ; Fri, 20 Jan 2012 18:45:27 -0800 (PST) Sender: linux-ext4-owner@vger.kernel.org List-ID: Hello, Amir I am evaluating ext4-snapshot (on github) for TAOBAO recently. The snapshot of an ext4 fs is READONLY now, but we do need to write data into snapshot. We also want using ext4-snapshot to do online-fsck on Hadoop clusters, but our hadoop clusters are using no-journal ext4 now. So we have some question 1. Will it be possible to implement a writable ext4-snapshot ? 2. Will it be possible to snapshot a no-journal ext4-fs ? 3. What's the difficult point of implementing above ? Any of your reply will be appreciate -- -- Best Regard Robin Dong