On Thursday 17 September 2009 19:17:55 Paolo Minazzi wrote:
> Hi,
> I have searched into the old posts and googling but I have not found any
> answer. I use an ARM board with NAND flash 1GB.
> I'm trying to use yaffs.
> I have done some tests and it seems much better that JFFS2 (regarding
> mount time).
>
> I have only a doubt.
>
> My system mount automatically yaffs2 file system at startup.
>
> If I write into yaffs2 partition and I use "umount" or "sync" before
> turn off the power, the successive mount command is very fast (about
> 0.1sec)
> If I write into yaffs2 partition and I don't use "umount" or "sync"
> before turn off the power, the successive mount command is very slow
> (about 13sec)
>
> A solution could be to have a background task :
> while [ 1 ]; do sync; sleep 1; done
> but obviously it is not good.
>
> I have not found any configuration option that solve this problem.

There isn't any.

>
> Have you got some suggestion ?

You might verify that your flash drivers are fast. Flash driver speed is the 
most critical part of getting a fast flash file system.

There is one feature that I have "paper designed" but not yet written and that 
is writing "block summaries". These would radically improve mount times when 
there is no checkpoint (sync/umount) data.

I would expect that to speed things to two seconds or so in your case.


-- Charles