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 1NwcA0-0006LX-LS for garchives@archives.gentoo.org; Tue, 30 Mar 2010 14:11:16 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 4EB6AE0D66 for ; Tue, 30 Mar 2010 14:11:16 +0000 (UTC) Received: from foo.birdnet.se (foo.birdnet.se [213.88.146.6]) by pigeon.gentoo.org (Postfix) with SMTP id DE284E08F0 for ; Tue, 30 Mar 2010 13:53:31 +0000 (UTC) Received: (qmail 12841 invoked by uid 501); 30 Mar 2010 13:53:30 -0000 Message-ID: <20100330135330.12840.qmail@stuge.se> Date: Tue, 30 Mar 2010 15:53:30 +0200 From: Peter Stuge To: gentoo-embedded@lists.gentoo.org Subject: Re: [gentoo-embedded] file system question Mail-Followup-To: gentoo-embedded@lists.gentoo.org References: <20100329184215.539920eb@osage.osagesoftware.com> 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-Disposition: inline In-Reply-To: <20100329184215.539920eb@osage.osagesoftware.com> X-Archives-Salt: b20e09ac-b2ae-45fe-b73f-ca59b9402e18 X-Archives-Hash: b16c435f57907d2751a59ecc5751001f David Relson wrote: > 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? I would consider ext3. In order to deal with sudden resets (or power loss) you really want a journalling filesystem. In that case you can lose data (and need to check for, and handle, that on startup) but at least the filesystem will be structurally ok. Which filesystem to use on the flash module depends mostly on the circumstances of systems in the field, such as how often they are serviced, service personnel skill level and so on. > Anybody have suggested readings so I can educate myself? Hm, not so much. :\ The situation you're in is probably pretty common, I have customers in the exact same situation, but it is very different from what JFFS2, YAFFS and friends are made for, which is that the filesystem actually has direct contact with the flash array. Any kind of consumer level flash module, including disk-on-modules, CF, SD, you name it, implements wear-levelling transparently. And everyone considers their particular wear-levelling to be an important competitive advantage, so they'll never give out details. The likes of JFFS2, YAFFS require immediate addressing of NAND flash chips connected to some bus, but that's never the case unless you're making your own PCBs. //Peter