From: Amir Goldstein Subject: Re: flashing large eMMC partitions with ext4 Date: Tue, 2 Aug 2011 20:52:56 +0300 Message-ID: References: <20110802160715.3069.qmail@web4212.mail.ogk.yahoo.co.jp> <20110802165757.GD2967@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Round Robinjp , Andreas Dilger , "linux-ext4@vger.kernel.org" To: "Ted Ts'o" Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:33755 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754639Ab1HBRw6 convert rfc822-to-8bit (ORCPT ); Tue, 2 Aug 2011 13:52:58 -0400 Received: by wyg8 with SMTP id 8so8802wyg.19 for ; Tue, 02 Aug 2011 10:52:57 -0700 (PDT) In-Reply-To: <20110802165757.GD2967@thunk.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Aug 2, 2011 at 7:57 PM, Ted Ts'o wrote: > On Wed, Aug 03, 2011 at 01:07:08AM +0900, Round Robinjp wrote: >> So that means I have thrown away some important part of >> the filesystem when I did truncate -s 1G, isn't it? >> Will things go wrong if I flash this 1G image to my eMMC >> partition (without using Yongqiang's new 64bit resize patches)? >> I need to understand whether Yongqiang's patch is absolutely >> necessary for this purpose or just a good thing to have. > > This is one of the reasons why I originally suggested using zero_free > and make_sparse to write the file system image. =A0It's a much, much, > MUCH simpler way of handling things, and it doesn't require resizing > the file system image, using truncate (and making sure you truncate t= o > the right size, etc.). > > With the method Amir talked about, it matters whether or not the file > system is mounted when you use resize2fs, whether you have the latest > resize patches, etc., etc. > I think it is fair to say that with if there are no constrains on the m= ethods used throughout the process, the zero_free + make_sparse is MUCH simple= r. However, my method is targeting an a-symmetric environment, where the person or organization responsible for generating the stock image have unlimited resources and knowledge, while the person or organization responsible = for burning that image to hundreds of devices are less capable or bound to = using old legacy systems, who just know how to burn an image of size N. Maybe Round can share more about the constrains of his environment. Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html