From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261300AbVFBJ0U (ORCPT ); Thu, 2 Jun 2005 05:26:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261314AbVFBJ0T (ORCPT ); Thu, 2 Jun 2005 05:26:19 -0400 Received: from mgw-ext04.nokia.com ([131.228.20.96]:5827 "EHLO mgw-ext04.nokia.com") by vger.kernel.org with ESMTP id S261300AbVFBJ0Q (ORCPT ); Thu, 2 Jun 2005 05:26:16 -0400 Date: Thu, 2 Jun 2005 12:17:59 +0300 From: Jarkko Lavinen To: "Artem B. Bityuckiy" Cc: Lennart Sorensen , linux-kernel@vger.kernel.org Subject: Re: Writing large files onto sync mounted MMC corrupts the FS Message-ID: <20050602091759.GA9161@angel.research.nokia.com> Reply-To: Jarkko Lavinen References: <20050601091320.GA1472@angel.research.nokia.com> <20050601131006.GL23621@csclub.uwaterloo.ca> <429EACC9.30303@yandex.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <429EACC9.30303@yandex.ru> X-Operating-System: GNU/Linux angel.research.nokia.com User-Agent: Mutt/1.5.9i X-OriginalArrivalTime: 02 Jun 2005 09:17:47.0393 (UTC) FILETIME=[F10B6710:01C56753] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 02, 2005 at 10:52:57AM +0400, ext Artem B. Bityuckiy wrote: > So, we should first ask whether this happens with *new* MMC cards or not. Flash manufactorers typically claim 100k erase cycles -- some even 1M. If FAT is updated after each written 512 byte block, filling 64MiB card in synchronous mode would cause over 100k FAT updates. One couldn't even fill a new 64MiB card without already breaking it. With asynchronous mount, one could limit the dirty_ratio from proc to reduce the sync time against sudden power loss. But wouldn't this have the same adverse wearing effect as with synchronous mode once the dirty_ratio is hit and writing still proceeds? Jarkko Lavinen