Graeme Fowler wrote:
> I've built a number of reasonably big Exim+Courier-IMAP load-balanced
> clusters which used NetApp backends for storage with the filesystems
> exposed to the IMAP servers over NFS. I don't recall having to tweak
> anything in the Exim config at all, certainly no "working around flaws",
> but I do recall having to set specific options on the IMAP daemon to do
> with concurrent access from multiple clients.
Are you sure about that last part? I've done this as well, and I can't
remember having to configure Couriers IMAP daemon to support this. In
fact, isn't Maildir supposed to support this access pattern "out of the
box"?
On a different but related note; can you remember if you did any tuning
of NFS share/mount options to get reasonable performance with Maildir on
NFS? Lack of performance (or more specifically latency with basic file
system operation such as link, unlink and open over NFS) made me switch
to using several servers with local storage and Couriers built-in
"clustering" support (which is basically an authenticated TCP forwarding
scheme).
Bob
