From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tokarev Subject: How to: determine if it's ext3 or ext2 mounted as ext4? Date: Mon, 10 Jan 2011 15:13:40 +0300 Message-ID: <4D2AF7F4.6040309@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: linux-fsdevel Return-path: Received: from isrv.corpit.ru ([86.62.121.231]:49297 "EHLO isrv.corpit.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752361Ab1AJMNn (ORCPT ); Mon, 10 Jan 2011 07:13:43 -0500 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hello. I'm performing conversion from ext3 to ext4 currently, on several nodes. The current plan is to remount them as ext4 first, next use tune2fs to update list of filesystem features, next to remount them again in order to actually turn the features on. The question is: what's the way to determine if the actual features used corresponds to ext3 or ext4? Or, in other words, if the last step in the above sequence has been completed or not? The filesystem superblock at this time will show ext4 already (since ext4-specific features are turned on), but actual features used will be ext3. Is there a way to determine if a remount is still needed? Besides, when I first use tune2fs (on a ext3-mounted fs) and next remount it, the filesystem wants an fsck pass, which finds checksum errors on all newly written files, and these errors can't be corrected automatically at boot if -y fsck flag is NOT used (default on Debian). So I had to remount them first and convert second. Thanks! /mjt