From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wi0-x233.google.com ([2a00:1450:400c:c05::233]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XuIBU-0005ng-KY for linux-mtd@lists.infradead.org; Fri, 28 Nov 2014 09:49:53 +0000 Received: by mail-wi0-f179.google.com with SMTP id ex7so10643599wid.12 for ; Fri, 28 Nov 2014 01:49:29 -0800 (PST) Message-ID: <54784527.8060205@gmail.com> Date: Fri, 28 Nov 2014 10:49:27 +0100 From: Angelo Dureghello MIME-Version: 1.0 To: "linux-mtd@lists.infradead.org" Subject: Re: UBI 1MiB size partition References: <5472F403.50702@gmail.com> <1417167595.11181.5.camel@sauron.fi.intel.com> In-Reply-To: <1417167595.11181.5.camel@sauron.fi.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Dear Artem, thanks for your reply. > UBI is a volume manager which is designed to manage the entire flash > chip. Sometimes system designers have one or two small partitions at the > beginning of the chip, and give the rest to UBI. > > You are using NAND flash, and UBI tries to reserve some amount of > eraseblocks for bad block handling. And the count of eraseblocks to > reserve is calculated from the entire chip size. So UBI says it wants > 20, but reserved only 4 - all the available blocks you have. So you do > not have any more blocks left, so you have no space. > > You really should re-think your design. 1MiB partition is too small, > there are too few eraseblocks. What if one or two of them become bad? > Yes, i realized this. A redesign of the partition scheme is needed at this stage. I cannot actually change the partition scheme for some reasons connected to the production process, but at least things are more clear now. Regards, Angelo