From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ew0-f49.google.com ([209.85.215.49]) by canuck.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1Q8CRP-0000gb-EC for linux-mtd@lists.infradead.org; Fri, 08 Apr 2011 14:13:40 +0000 Received: by ewy3 with SMTP id 3so1196080ewy.36 for ; Fri, 08 Apr 2011 07:13:36 -0700 (PDT) Subject: Re: time to mount static volume seems to be too long From: Artem Bityutskiy To: Bastian.Ruppert@sewerin.de In-Reply-To: <1302271177.2834.26.camel@localhost> References: <1302271177.2834.26.camel@localhost> Content-Type: text/plain; charset="UTF-8" Date: Fri, 08 Apr 2011 17:10:47 +0300 Message-ID: <1302271847.2834.34.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd@lists.infradead.org, Detlev Zundel Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2011-04-08 at 16:59 +0300, Artem Bityutskiy wrote: > Hello, > > On Fri, 2011-04-08 at 14:48 +0200, Bastian.Ruppert@sewerin.de wrote: > > [ubifs] > > mode=ubi > > image=/opt/rfsb/build/images/image.ubifs > > vol_id=0 > > vol_size=46080KiB > > vol_type=static > > vol_name=rootfs > > vol_flags=autoresize > > > > I can mount the rootfs, but with this configuration the rootfs mount > > time is about 8 Seconds for the image in a 71MB Partition. > > IMHO, it makes little sense to use UBIFS on top of static volumes. > Static volumes were really meant to store raw blob of data, where you > want UBI to protect it with CRC for you. > > UBIFS has its own CRC protection, so with static volume you get double > CRC. Note, to force UBIFS checking data CRC on read you need to use > "chk_data_crc" option, see here: > > http://www.linux-mtd.infradead.org/doc/ubifs.html#L_checksumming > > IOW, you do not need double-work. BTW, if you appreciate the help from community and want to contribute, it'd be nice if you wrote a short text to our FAQ: "why a dynamic volume is faster to access than a static volume of the same size?" You can add it to this web page: http://www.linux-mtd.infradead.org/faq/ubi.html To do this, clone http://git.infradead.org/mtd-www.git edit faq/ubi.xml, type "make", make sure it compiles. Then open it with your browser, check it looks good in html form, then send the patch. Thanks! :-) -- Best Regards, Artem Bityutskiy (Артём Битюцкий)