On Tue, May 28, 2013 at 06:31:47AM -0500, Thanumalayan Sankaranarayana Pillai wrote: > Woody, this mailing list might not be the best place to discuss problems > with YAFFS2. Saying that, a simple test could be to almost fully fill the > YAFFS2 partition with a bunch of files, then read those files and make sure > the files have the data they are supposed to have. Files should have > sensible content in them (and are not just filled with zeroes). Also, I'm > assuming that you already have some experience with YAFFS2, correct?
No, I don't have any real experience in using YAFFS2. Today, I tried to subscribe its mailing list, but don't get the confirmation email, wired. > Otherwise, maybe there is some requirement you haven't satisfied, like > erasing all of your partition prior to using it? Interesting... Could you talk more 'bout that? As I said, the target system was built by our external vendor, I don't know their process. Can I check if it's correctly done? Erasing Yaffs2 means something like 'mke2fs' on a ext* file system? Thanks. > > > On Mon, May 27, 2013 at 11:44 PM, Woody Wu <narkewo...@gmail.com> wrote: > > > On Tue, May 28, 2013 at 03:08:55AM +0100, Simon Slavin wrote: > > > > > > On 28 May 2013, at 2:37am, Woody Wu <narkewo...@gmail.com> wrote: > > > > > > > How do you guys think about this: if NAND has an > > > > IO problem, Yaffs2 should recover it or forward the error to > > > > applications, right? > > > > > > Arguably. The file system can send an error back to the application. > > > If something does that to SQLite3 SQLite3 will then return the result > > > SQLITE_IOERR. If your program is correctly looking at the results > > > returned from every SQLite3 API call, and it's not seeing that error, > > > it would seem that yaffs2 is not doing the correct thing in this case. > > > And from what you wrote it seems that rather than return an error to > > > the program, yaffs2 prefers to write an error message to the console. > > > Which is not what these things are meant to do. > > > > > > > > > On 28 May 2013, at 2:40am, Woody Wu <narkewo...@gmail.com> wrote: > > > > > > > Can you experts explains why a cheap Flash drive can harm an > > > > application such as sqlite? > > > > > > > Does you mean these cheap drive was cheating > > > > with ECC? > > > > > > It might just be so bad that it doesn't even realise something is > > > wrong. You write something to sector 2336 and later read sector 2336 > > > and expect to get the same thing back, but instead it returns the > > > contents of sector 2338. Faulty hardware, perhaps. > > > > > > > Otherwise, filesystem should be able to capture IO error (fix > > > > it or forward), right? > > > > > > If by 'forward' you mean to tell the application something went wrong, > > > then right. But the file system might not know anything is wrong. It > > > asked for sector 2336 and it got some data. How is it meant to know > > > the data it retrieved came from the wrong place on the chip ? > > > > > > On 28 May 2013, at 2:33am, Woody Wu <narkewo...@gmail.com> wrote: > > > > > > > How can I tell what's the current VFS that I was using? Thanks. > > > > > > Actually, just ignore that. You couldn't do anything about it even if > > > you knew. From what Doctor Hipp wrote, I suspect that yaffs2 is > > > faulty. > > > > > > Simon. > > > _______________________________________________ > > > sqlite-users mailing list > > > sqlite-users@sqlite.org > > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > > Very clear explained, Simon. Thanks. > > > > On the other hand, I still want to write some test code to exposure > > Yaffs2's defects on my target. I already wrote a simple one, which just > > repeatly write to a file and read back to compare its conents. Probably > > it's too simple to trigger an error. After 72 hours, it haven't reported > > any error. I really like to hear any suggestion on writing such a test > > from your experts. Anyway, if the original case was really caused by > > Yaffs2, I belive there must exist a test to capture it. Do you agree? > > > > -woody > > > > > > > > > > > > -- > > woody > > I can't go back to yesterday - because I was a different person then. > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users@sqlite.org > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users -- woody I can't go back to yesterday - because I was a different person then. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
