From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from samar.sasken.com ([164.164.56.2]) by pentafluge.infradead.org with esmtp (Exim 3.22 #1 (Red Hat Linux)) id 16bZcG-0005At-00 for ; Fri, 15 Feb 2002 04:04:57 +0000 Message-ID: <3C6CD9BD.7386D3F2@sasken.com> Date: Fri, 15 Feb 2002 09:49:49 +0000 From: Ashok M Padmanaban MIME-Version: 1.0 To: MTD for Linux , navin.boppuri@newisys.com Subject: RE: Weird status information on JFFS2 File System Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-mtd-admin@lists.infradead.org Errors-To: linux-mtd-admin@lists.infradead.org List-Help: List-Post: List-Subscribe: , List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: Hi Navin Your Jffs2 file system size is 1MB Jffs2 reserves around 5 sectors( erase sectors) for garbage collection. So even when ur FS is empty , command df will show that 5 erase sectors have been already occupied Regards ashok Navin Boppuri wrote: > Well, I guess I think I know what the problem is. I should not use /dev/zero to create files to test the file system size. I decided to use /dev/core instead and that actually creates the correct sized file. > > But I still dont understand why the status of my file system is so screwed up. Even with an empty file sytem, it shows 64% used. And I am only able to write around 375K of data into this partition, which is actually 1MB. > > Navin. > > -----Original Message----- > From: Navin Boppuri > Sent: Thursday, February 14, 2002 1:29 PM > To: linux-mtd@lists.infradead.org > Subject: Weird status information on JFFS2 File System > > Hello all, > > I have a JFFS2 file system successfully installed on my flash device. Here is the output of the drivers during the Linux kernel boot. I have 1MB of flash partition installed as my flash device( I have two 16bit AMD flash devices connected on a 32 bit bus as one device). > > sp flash device: 1000000 at 40000000 > Amd/Fujitsu Extended Query Table v1.1 at 0x0040 > number of CFI chips: 1 > Creating 1 MTD partitions on "Service Processor flash device": > 0x00f00000-0x01000000 : "Flash file system" > mtd: Giving out device 0 to Flash file system > > After I mount my file system using the following command, > mount -t jffs2 /dev/mtdblock0 /mnt/jffs2 > > I confirm that the file system is mounted by looking at /proc/mounts. > > root@sp_06:/mnt/jffs2# cat /proc/mounts > /dev/root / nfs rw,v2,rsize=4096,wsize=4096,hard,udp,nolock,addr=10.10.30.39 0 0 > proc /proc proc rw 0 0 > devpts /dev/pts devpts rw 0 0 > /dev/mtdblock0 /mnt/jffs2 jffs2 rw 0 0 > > I now look at the disk usage using the df command > > root@sp_06:/mnt/jffs2# df > Filesystem 1k-blocks Used Available Use% Mounted on > /dev/root 30237928 12751536 15950380 45% / > /dev/mtdblock0 1024 644 380 63% /mnt/jffs2 > > root@sp_06:/mnt/jffs2# ls -al > total 4 > drwxr-xr-x 1 root root 0 Jan 1 00:00 . > drwxr-xr-x 3 1342 root 4096 Jan 25 2002 .. > > I am surprised to see 63% usage without anything in the file system. > > I now create the following three files doing this: > > dd if=/dev/zero of=tmp.out bs=1M count=4 conv=sync > dd if=/dev/zero of=tmp2.out bs=1M count=4 conv=sync > dd if=/dev/zero of=tmp3.out bs=1M count=4 conv=sync > > I run out of space while trying to create the tmp3.out command. But I am able to create almost 10MB of data in my 1MB file system. > > root@sp_06:~# ls -al /mnt/jffs2 > total 10152 > drwxr-xr-x 1 root root 0 Jan 1 00:00 . > drwxr-xr-x 3 1342 root 4096 Jan 25 2002 .. > -rw-r--r-- 1 root root 4194304 Jan 1 03:01 tmp.out > -rw-r--r-- 1 root root 4194304 Jan 1 03:01 tmp2.out > -rw-r--r-- 1 root root 2002944 Jan 1 03:01 tmp3.out > > root@sp_06:~# df > Filesystem 1k-blocks Used Available Use% Mounted on > /dev/root 30237928 12751536 15950380 45% / > /dev/mtdblock0 1024 932 92 92% /mnt/jffs2 > > I doing something really wrong here. What's going on? The kernel messages are all correct. Then how am I able to access 10MB of flash in this file system? I am only mapping the last 1MB of flash which is 16MB in size. And I am confused about the status of my file system each time I create files. > > Can someone give me some pointers on this? Thank you. > > Navin. > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/ > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/