Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262008AbUFQT7Y (ORCPT ); Thu, 17 Jun 2004 15:59:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262963AbUFQT7Y (ORCPT ); Thu, 17 Jun 2004 15:59:24 -0400 Received: from meetpoint.leesburg-geeks.org ([66.63.28.250]:2058 "EHLO meetpoint.home") by vger.kernel.org with ESMTP id S262008AbUFQT7R (ORCPT ); Thu, 17 Jun 2004 15:59:17 -0400 Message-ID: <40D1F809.8030405@leesburg-geeks.org> Date: Thu, 17 Jun 2004 15:59:05 -0400 From: Ken Ryan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030915 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Daniel Egger CC: Hans Reiser , Timothy Miller , linux-kernel@vger.kernel.org, pla@morecom.no Subject: Re: mode data=journal in ext3. Is it safe to use? References: <40D1B110.7020409@leesburg-geeks.org> <40D1C18B.1030907@techsource.com> <40D1D2F0.7080102@namesys.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1524 Lines: 45 Daniel Egger wrote: > On 17.06.2004, at 19:20, Hans Reiser wrote: > >> Actually, most compact flash devices DO do wear leveling, from what I >> have heard. > > > Care to mention sources? I'd be surprised if they did simply because > it'll cost money that could be earned otherwise. Also I think you > confuse bad block remapping with wear leveling and even the former > I haven't experienced so far. > > CF disks were designed for simply the reason of having an empty disk, > writing data onto it up to a certain level, reading it a few times > and emptying the disk again. So except for the organizational blocks > and "the end" of a disk which tends to get rarely hit there're a > well distributed write utilization. > > Servus, > Daniel For example: Just bop over to the Sandisk website, go the the OEM section, and download the manual/datasheet for CF devices. The wearlevel command itself isn't supported (I'm ignorant of flash on IDE, I assume it is intended to mean full scrub-style wear levelling) but they note they roll simplified wear levelling into the erased page pool. Doing that is an easy way to get part of the way there without needing a lot of infrastructure. And for the fill-read-empty usage model it's perfectly fine. ken - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/