[Dovecot] Best Cluster Storage

[Jonathan Tripathy]

Hi Everyone,

I wish to create a Postfix/Dovecot active-active cluster (each node will 
run Postfix *and* Dovecot), which will obviously have to use central 
storage. I'm looking for ideas to see what's the best out there. All of 
this will be running on multiple Xen hosts, however I don't think that 
matters as long as I make sure that the cluster nodes are on different 
physical boxes.

Here are my ideas so far for the central storage:

1) NFS Server using DRBD+LinuxHA. Export the same NFS share to each mail 
server. Which this seems easy, how well does Dovecot work with NFS? I've 
read the wiki page, and it doesn't sound promising. But it may be outdated..

2) Export block storage using iSCSI from targets which have GFS2 on 
DRBD+LinuxHA. This is tricky to get working well, and it's only a theory.

3) GlusterFS. Easy to set up, but apparently very slow to run.

So what's everybody using? I know that Postfix runs well on NFS 
(according to their docs). I intend to use Maildir

Thanks