From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wy0-f177.google.com ([74.125.82.177]) by canuck.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1Q8CGX-0000a8-SO for linux-mtd@lists.infradead.org; Fri, 08 Apr 2011 14:02:26 +0000 Received: by wyb28 with SMTP id 28so3820787wyb.36 for ; Fri, 08 Apr 2011 07:02:24 -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: References: Content-Type: text/plain; charset="UTF-8" Date: Fri, 08 Apr 2011 16:59:37 +0300 Message-ID: <1302271177.2834.26.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: , 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. > When changing the vol_type attribute to dynamic, the mount time is > much shorter (about 1 Second). This is because UBI change the CRC of the whole static volume, this is where you spend time. > The point of interest are the timings. > The static volume is designed for speed up booting and mounting, isn t > it? No, I think it was originally designed to store short blobs of data like a configuration file. -- Best Regards, Artem Bityutskiy (Артём Битюцкий)