From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tao Ma Subject: [RFC] Add inline data support in ext4 Date: Tue, 27 Sep 2011 15:11:09 +0800 Message-ID: <4E81770D.8090309@tao.ma> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: Ted Ts'o , ext4 development , Andreas Dilger Return-path: Received: from oproxy6-pub.bluehost.com ([67.222.54.6]:38167 "HELO oproxy6-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751348Ab1I0HLU (ORCPT ); Tue, 27 Sep 2011 03:11:20 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Ted, Andreas and the list, As you may already know, we are beginning to evaluate the bigalloc features in our production system. The performance looks promising, but we have also met with a severe problem with bigalloc. As ext4 now allocates one block for the directory even if it is empty, it is really space-consuming for some applications which uses hashes and create large numbers of directories(AUFS in squid for example). ocfs2 now uses inline data for a new created file/dir so that some small ones can have their data within the inodes. It is really helpful and we are considering adding the same to ext4. What is your option? I haven't been involved in ext4 for a long time, so I am not sure whether there was a similar try which was abandoned finally. Anyway, with bigalloc added, it is really needed for us to support inline data now. Thanks Tao