I've just converted from mbox to maildir Right now there are some users with 500 files in a directory, I expect this go grow.
I expect this figure to grow. RaiserFS is looking good. The benefits of running a central storage server and a bunch of seperate web/smtp/pop3/spamfiltering/ftp/ servers, one storage server running not much more than NFS all connected with a cheap Gigbit switch are also appealing to me. Is there any benefit to RaiserFS if I am accessing it via NFS ?