ext4 and extremely slow filesystem traversal

[Theodore Ts'o]

On Wed, Mar 13, 2013 at 12:56:15AM +0100, Vincent Caron wrote:
> 
>   I even tried a hack which tries to sort directories while traversing
> the filesystem to no avail.

Did you sort results from readdir() by inode number?  i.e., such as
what the following LD_PRELOAD hack does?

https://git.kernel.org/cgit/fs/ext2/e2fsprogs.git/tree/contrib/spd_readdir.c?h=maint

>   Right now I don't even know how to analyze my filesystem further.
> Sorry for not being able to describe it more accurately. I'm in search
> for any advice or direction to improve this situation. While keeping
> using ext4 of course :).

Try running "e2fsck -fv /dev/XXX" and send me the output.

Also useful would be the output of "e2freefrag /dev/XXX" and "dumpe2fs -h"

	     	    	     	 	   - Ted