From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-bw0-f43.google.com ([209.85.214.43]) by canuck.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1PTZPL-0006Vk-Qx for linux-mtd@lists.infradead.org; Fri, 17 Dec 2010 12:27:46 +0000 Received: by bwz14 with SMTP id 14so801261bwz.30 for ; Fri, 17 Dec 2010 04:27:31 -0800 (PST) Subject: Re: Static UBI volumes and ubiupdatevol ? From: Artem Bityutskiy To: Ricard Wanderlof In-Reply-To: References: <1292516353.2364.101.camel@localhost> Content-Type: text/plain; charset="UTF-8" Date: Fri, 17 Dec 2010 14:26:57 +0200 Message-ID: <1292588817.2412.7.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Ricard =?ISO-8859-1?Q?Wanderl=F6f?= , "linux-mtd@lists.infradead.org" Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2010-12-17 at 10:33 +0100, Ricard Wanderlof wrote: > > The same with UBIFS - we never write when we are mounted R/O. There are > > many ubifs_assert()s to check this as well. > > ... but UBI might still do writes during the course of scrubbing I guess, > unless ... Yes, you are right. > > > so it is possible to use a > > > simple checksum to verify data integrity. > > > > You can do this with UBIFS I think, did not try though. > > What I meant was 'a simple checksum on the raw mtd partition', which can't > work with UBIFS as the UBI erase counters etc can change over time as a > result of scrubbing. Ah, yes, you see, you know the things quite well yourself :-) > I guess I could read from the /dev/ubix_y device to just get the raw UBIFS > data which shouldn't change even in the event of scrubbing? Or should I > use gluebi to get both a raw mtd partition corresponding to the raw UBIFS > data, as well as using UBIFS (on /dev/ubix_y) for the file system? No, gluebi is not needed, it would just give you an /dev/mtdZ device with contents equivalent to /dev/ubiX_Y -- Best Regards, Artem Bityutskiy (Артём Битюцкий)