From: Yongqiang Yang Subject: Re: ext4 online resize and robustness to interruption Date: Tue, 3 Apr 2012 18:58:29 +0800 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Ext4 Developers List , Andreas Dilger To: Daniel Drake Return-path: Received: from mail-ob0-f174.google.com ([209.85.214.174]:48532 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751458Ab2DCK6a (ORCPT ); Tue, 3 Apr 2012 06:58:30 -0400 Received: by obbtb18 with SMTP id tb18so3404364obb.19 for ; Tue, 03 Apr 2012 03:58:29 -0700 (PDT) In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Apr 2, 2012 at 11:17 PM, Daniel Drake wrote: > Hi, > > I think this question has been asked before, but I'd like to revisit > it given the recent rework of ext4 online resizing: > > How robust is ext4 online resize in the face of unexpected > interruption (i.e. sudden loss of power)? Yep! It is only robust when journal is used. In no journal mode, it is not. Yongqiang. > > The context here is that OLPC will now performing an online resize > upon first boot of the system. Our laptops are frequently used in very > remote places with unreliable power, and given that we work in large > numbers, we're going to see some cases where the system lost power > during the resize operation. What is the expected effect here - will > the system boot up again just fine (perhaps with the original > partition size), and is then repeating the resize operation expected > to be safe and reliable? > > Thanks, > Daniel -- Best Wishes Yongqiang Yang