From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1NwaEK-0003s8-TS for garchives@archives.gentoo.org; Tue, 30 Mar 2010 12:07:37 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 840B8E0967 for ; Tue, 30 Mar 2010 12:07:36 +0000 (UTC) Received: from mail.osagesoftware.com (osagesoftware.com [216.144.204.42]) by pigeon.gentoo.org (Postfix) with ESMTP id EEE7CE0980 for ; Tue, 30 Mar 2010 11:47:35 +0000 (UTC) Received: from osage.osagesoftware.com (osage.osagesoftware.com [192.168.1.10]) by mail.osagesoftware.com (Postfix) with ESMTP id 5EBCE7BC34; Tue, 30 Mar 2010 07:47:35 -0400 (EDT) Date: Tue, 30 Mar 2010 07:47:35 -0400 From: David Relson To: gentoo-embedded@lists.gentoo.org Cc: ikrabbe.ask@web.de Subject: Re: [gentoo-embedded] file system question Message-ID: <20100330074735.78d6ad5c@osage.osagesoftware.com> In-Reply-To: <20100330084025.GA18297@ask.eoa.intra> References: <20100329184215.539920eb@osage.osagesoftware.com> <20100330084025.GA18297@ask.eoa.intra> Organization: Osage Software Systems, Inc. X-Mailer: Claws Mail 3.7.5 (GTK+ 2.18.7; x86_64-pc-linux-gnu) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-embedded@lists.gentoo.org Reply-to: gentoo-embedded@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Archives-Salt: c8436d00-0771-42a0-a289-95e7fb5006ed X-Archives-Hash: 098659c28a6a4db35cd7ceab72159a3c On Tue, 30 Mar 2010 10:40:25 +0200 Ingo Krabbe wrote: > On Mon, Mar 29, 2010 at 06:42:15PM -0400, David Relson wrote: > > G'day, > > > > I'm porting the software for an embedded medical device from DOS to > > Linux and am wondering which file systems are appropriate and which > > are not. The device's mass storage is a Disk-on-Module solid state > > flash drive. Data is presently written at approx 100 bytes every > > 30 seconds but that might change to 100 bytes every second. The > > device has a watchdog (recently activated) and during today's > > session it was triggered and wiped out my file system. > > > > Anybody have recommendations on which file system to use and the > > appropriate settings? > > > > Anybody have suggested readings so I can educate myself? > > First I would read about Wear Levelling (Wikipedia). Maybe your > device already implements TrueFFS or ExtremeFFS with low-level wear > levelling, so it might be enough to just use any other file system > upon. Then I would choose a simple ext2 file system, though I can't > tell the wear levelling really works. Are there methods to debug > that? > > I think the best choose for you might be a JFFS2 Filesystem. Or just > choose one from "Flash file system" in Wikipedia. > > bye ingo Hello Ingo, I've been using ext2 and have encountered some problems. In addition to porting from DOS to Linux, the PC-104 board that has been used for years has reached end-of-life, so there's a new PC-104 board that's also involved. With the new board life has been good. With the old board a file system problem has been encountered many times. For reasons totally unclear (at least to me), all of a sudden a file can't be read or a shared library doesn't load. When I check using ls, the message "Stale NFS file handle" appears. The device has _never_ been on a network, so NFS doesn't actually play any role in the device's life cycle. This has been happening at least a couple of times a week for the last month. Often it happens several times in the same day. The file handle problem has only happened with the old board, never with the new. As there are several thousand "old board" devices in use, the Linux port needs to support them. FWIW, the cpu is a 486 and we're using the 2.6.29.6 kernel. Regards, David P.S. The "flash file system" suggestion is appreciated! I'll check into it.