question about gluster 3.0.4 and gluster-fuse (latest) on 2 centos 5.4 servers

[mve at pcintelligence.nl (Michiel van Es)]

Hello,

I am running 2 servers with CentoS 5.4 32 bit with 1 GB memory and 2 
Xeon 3,4 Ghz cpu's.
Both are server and client.
Gluster 3.0.4 source is used and the latest fuse from glusterfs.
I put the Qmail maildir on the gluster mount.
I notices that IMAP connections are really slow and see a lot of gluster 
load whenever I receive a mail or send an email.

This is my glusterfsd.vol on both servers:

-bash-3.2# less /etc/glusterfs/glusterfsd.vol

volume posix
   type storage/posix
   option directory /data/export
end-volume

volume locks
   type features/locks
   subvolumes posix
end-volume

volume brick
   type performance/io-threads
   option thread-count 8
   subvolumes locks
end-volume

volume server
   type protocol/server
   option transport-type tcp
   option auth.addr.brick.allow 194.145.200.1*
   subvolumes brick
end-volume

and the client glusterfs.vol:

volume remote1
   type protocol/client
   option transport-type tcp
   option remote-host server1.pcintelligence.nl
   option remote-subvolume brick
end-volume

volume remote2
   type protocol/client
   option transport-type tcp
   option remote-host server2.pcintelligence.nl
   option remote-subvolume brick
end-volume

volume replicate
   type cluster/replicate
   subvolumes remote1 remote2
end-volume

volume writebehind
   type performance/write-behind
   option window-size 1MB
   subvolumes replicate
end-volume

volume cache
   type performance/io-cache
   option cache-size 512MB
   subvolumes writebehind
end-volume



Are there any perfomance tweaks I can make to speed up the small files 
and Qmail's maildir with dovecot?

Kind regards,

Michiel