From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.shareable.org ([81.29.64.88]) by canuck.infradead.org with esmtps (Exim 4.54 #1 (Red Hat Linux)) id 1F9rJC-0007mY-P4 for linux-mtd@lists.infradead.org; Thu, 16 Feb 2006 17:09:07 -0500 Date: Thu, 16 Feb 2006 22:08:54 +0000 From: Jamie Lokier To: Charles Manning Message-ID: <20060216220854.GA27562@mail.shareable.org> References: <200602091126.10462.manningc2@actrix.gen.nz> <200602141510.12749.wolfgang.mues@auerswald.de> <200602161617.04905.manningc2@actrix.gen.nz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200602161617.04905.manningc2@actrix.gen.nz> Cc: linux-mtd@lists.infradead.org, Wolfgang =?iso-8859-1?Q?M=FCes?= Subject: Re: Questions about NAND (double)bit errors List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Charles Manning wrote: > > About bad block detection: what is your oppinion about partitioning the > > flash (the programs in a read-only partition, the data in r/w). > > This gets fs specific. With YAFFS (and I assume JFFS2, but consult > an expert), grabage collection will force read-only files to get > rewritten occasionally. Thus for ultimate reliability it is > probably a GoodIdea to seperate the read-only stuff into a seperate > partition. This is also a GoodIdea in that a smaller partition > mounts faster (true for YAFFS and JFFS2). So if all your kernel + > mount stuff is seperated from your rw stuff things will probably dgo > better. Absolutely. I've been testing 40 devices lately, and in 2 weeks, 5 of them (out of 40) have corrupted files in JFFS2 when those files aren't being written. I haven't seen any errors in the ROMFS partitions. I'm still getting round to analysing the corrupt files / filesystems, because that failure rate is too high even for configuration files that are written from time to time. These are 8MB chips, so presumably NOR. -- Jamie