[Dovecot] Dovecot and SATA Backend

[alex handle]

> But "faster" is not always the way to measure things.
>
> In this topic, I think that raw disk access speed is not a critical
> value; I've tested our setup with maildir on NFS and performance is
> close enough to local disks. Given this, I prefer the extra features
> our NAS/SAN setup gives us, like having data replication between
> phisically separated disks in a couple of clicks ,redundant paths to
> data, easier management, ...

In my test local storage was always ~ 2 times faster than nfs.

if you have the deep pockets to buy all the storage gear and
replication licenses/maintainence  then it's for sure far better.
But if you are an isp, you have to sell the storagespace for pennies.
So we came up with a cheap robust and scalable storage solution
special to our mailsetup.
It Supports HA with blocklevel-replication and snapshots with lvm so
it's even some what manageable.

Another point against nfs is that i wanted to avoid potential
locking/coruption problems.
I know it can be solved by always redirecting the same user to the
same server, but then again i loose the convenience of nfs.
So i ditch nfs complety and use multiple storage servers in pairs
running dovecot.