From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.nokia.com ([192.100.105.134] helo=mgw-mx09.nokia.com) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1Lu0pU-0001TS-0g for linux-mtd@lists.infradead.org; Wed, 15 Apr 2009 08:50:58 +0000 Subject: Re: ubifs error when do bonnie++ test From: Artem Bityutskiy To: Jason Liu In-Reply-To: References: <49D47252.3020701@nokia.com> <1239366421.3390.12.camel@localhost.localdomain> <1239689874.3390.88.camel@localhost.localdomain> Content-Type: text/plain; charset="UTF-8" Date: Wed, 15 Apr 2009 11:50:05 +0300 Message-Id: <1239785405.3390.173.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Linux mtd , Adrian Hunter Reply-To: dedekind@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2009-04-15 at 16:44 +0800, Jason Liu wrote: > We use 2 MLC nand flash to simulate this virtual device. Each NAND > chip is 4K page size with 218 OOB size. > We can parallel program each NAND chip in order to improve the write > performance. I see. Then you want to teach your setup understand sub-pages. In your case the sub-page will be 2K. Then you'll waste much less space in UBI. See here: http://www.linux-mtd.infradead.org/doc/ubi.html#L_subpage Note, with this all I/O will be in page size units (8K), only UBI headers I/O will be in sub-page size units. So with this you will preserve I/O speed, but lessen flash space wastage. And just in case, please, make sure you have read this: http://www.linux-mtd.infradead.org/faq/ubifs.html#L_ubifs_mlc -- Best regards, Artem Bityutskiy (Битюцкий Артём)