In message <20040422085859.C6134424CD at denx.de> you wrote: > > Because our board will be turned on and off frequently, so I think "high > stability" is the important, and a R/W file system is prefer selection too! > Another performances such as speed of booting is not the focus!
How about speed when accessing (especially reading) files? What about memory footprint? > Now our system can runs ok, I use EXT2 FS as the root file system build in a > 32M DOC2000, but it seems it's unstable! You asked adbout a filesystem for flash before - this is NOT the same as DOC or even CompacfFlash, as these devices use an internal controller which may perfom certain operations like wear levelling etc. So what do you want to know - filesystems for plain flash memory, or for DOC? The ext2 filesystem is extremley well tested and can be considered to be very stable. Howebver, it was not designed to be used like you attempt to do - i. e. just powering off the device. You must always unmount an ext2 filesystem (or at least remount it read-only_)_ before shutting doen the system. > In any time when the linux is starting, you turn off the power, maybe the > root file system will crash! Yes, this is the logical consequence of your mis-use. > I have serval questions want to be confirmed: > 1. Whether the DOC2000 is unstable? NO. It is working perfectly fine in many applications. > 2. Can I build a EXT2 FS in flash? Yes, you can. Both in flash memory and on a DOC device. BUt you have to be aware of the restrictions (i. e. ext2 requires to be unmounted before shutdown, and it does not implement any wear levelling which may be useful on writable flash filesystems). > 3. How to avoid the file system crash in embed linux system? Don't do things which are outside of the specifications of the software. Best regards, Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de "I like your game but we have to change the rules." ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
