[Dovecot] Providing shared folders with multiple backend servers

[Sven Hartge]

Stan Hoeppner <stan at hardwarefreak.com> wrote:

> The more I think about your planned architecture the more it reminds
> me of a "shared nothing" database cluster--even a relatively small one
> can outrun a well tuned mainframe, especially doing decision
> support/data mining workloads (TPC-H).

> As long as you're prepared for the extra administration, which you
> obviously are, this setup will yield better performance than the NFS
> setup I recommended.  Performance may not be quite as good as 4
> physical hosts with local storage, but you haven't mentioned the
> details of your SAN storage nor the current load on it, so obviously I
> can't say with any certainty.  If the controller currently has plenty
> of spare IOPS then the performance difference would be minimal.

This is the beauty of the HP P4500: every node is a controller, load is
automagically balanced between all nodes of a storage cluster. The more
nodes (up to ten) you add, the more performance you get.

So far, I have not been able to push our current SAN to its limits, even
with totally artificial benchmarks, so I am quite confident in its
performance for the given task.

But if everything fails and the performance is not good, I can still go
ahead and buy dedicated hardware for the mailsystem.

The only thing left is the NFS problem with caching Timo mentioned, but
since the accesses to a central public shared folder will be only a
minor portion of a clients access, I am hoping the impact will be
minimal. Only testing will tell.

Grüße,
Sven.

-- 
Sigmentation fault. Core dumped.