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Re: FW: Mount JFFS2 root file system issue


Hello Chris,

We would be interested in eCosCentric's JFFS2 if - in order of importance
- it would need less RAM per file
- it would have less "strange" problems
* if I drive JFFS2 to its limits (put it full, use very big files, put many small files in 1 directory) it can get corrupted
* our simple FTP server corrupts JFFS2 if you put over 180 files with a FTP client on PC
* the more you use JFFS2 (add and remove files), the more it trashes itself, so the more delay all actions have
- it would be faster in opening files (especially in a directory with over 1000 files)


Therefore, I want to repeat the warning from Thomas Köller: "Do not use large JFFS2 file systems if RAM is a scarce resource!" (http://sourceware.org/ml/ecos-discuss/2003-10/msg00247.html).
And that is just what we have done..


Kind regards,
Jürgen

Chris Zimman wrote:

I am also struggling with JFFS2, and I did already a lot of tests.
There more files you have in jffs2, the longer it takes to mount:
- per inode, 16 B (static) or 24 B (dynamic) are written in RAM
- per file, more or less 72 B (found by testing, I should check the
jffs2 sources..) are written in RAM
Also, during mounting, a garbage collect is done. As explained below,
the file system (the journal) is then checked. And the bigger the
flash,
the more time it can take.

Indeed, once the boot time is long, you can only solve it by formatting
jffs2.

I can reproduce this this way: I put 1000 files in 1 directory, then I
delete 997 of them, and still mounting and also opening of 1 file takes
very long. To go more in detail: mounting goes from 11s to 10s, but
opening 1 file goes from 570ms to 820ms.



Just so you're aware, eCosCentric does provide a supported and working version of JFFS2 with eCosPro.

--Chris





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