[Linux-cluster] GFS2 poor performance

[ffv at tjpr.jus.br]

Hi all,
 
I´m getting a very poor performance using GFS2.
I have two qmail (mail) servers and one gfs2 filesystem shared by them.
In this case, each directory in GFS2 filesystem may have upon to 10000 files (mails)
 
The problem is in performance of some operations like ls, du, rm, etc
for example, 
 
# time du -sh /dados/teste
40M     /dados/teste
 
real    7m14.919s
user    0m0.008s
sys     0m0.129s

this is unacceptable
 
Some attributes i already set using gfs2_tool:
 
gfs2_tool settune /dados demote_secs 100
gfs2_tool setflag jdata /dados
gfs2_tool setflag sync /dados
gfs2_tool setflag directio /dados
 
but the performance is still very bad
 
 
Anybody know how to tune the filesystem for a acceptable performance working with directory with 10000 files?
thanks for any help