From: Felipe Monteiro de Carvalho Subject: Re: Beginner questions about ext4 Date: Mon, 15 Jul 2013 18:09:03 +0200 Message-ID: References: <20130623115953.GA16193@thunk.org> <20130715134357.GA26359@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-ext4@vger.kernel.org To: "Theodore Ts'o" Return-path: Received: from mail-pd0-f169.google.com ([209.85.192.169]:53892 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932535Ab3GOQJE (ORCPT ); Mon, 15 Jul 2013 12:09:04 -0400 Received: by mail-pd0-f169.google.com with SMTP id y10so10939877pdj.0 for ; Mon, 15 Jul 2013 09:09:03 -0700 (PDT) In-Reply-To: <20130715134357.GA26359@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: Hello, Thanks. Now I think that I am getting closer to something more concrete. My superblock says: superblock^.s_blocks_per_group = 32768 superblock^.s_inodes_per_group = 8080 superblock^.s_log_block_size = 2 -> so each block has 4k bytes And when reading the root "/" I obtain the following information for the directory /bin/ : inode=8081 So I calculate that it should have: groupnr=1 (because it is above 8080 inodes per group) offset for groupnr 1 --> 4k * 32768 = 0x8000000 But I have utilized a hex editor (oh boy, it was hard to find one that would read files over 4GB....) And the directory listing of /bin/ is located in aprox. near 0x21B0000 As if each block group would have a size of 0x2000000 .... but this size would be valid I would expect if superblock^.s_blocks_per_group=8192 ... Any idea what I missed here that the calculations went wrong? thanks, -- Felipe Monteiro de Carvalho