dovecot - Mar 2011 - Dovecot 2.0 in Active-Standby configuration

Hi,
I am planning to use Dovecot 2.0 as a Mail server for a Voicemail system.
There is not much traffic so I am not concerend about scaling. However
redudancy is an issue.
I need to have two Dovecot servers installed on two different farms and
setup HA between the two. I would prefer that the HA would be automatically.
I have two different storage machines with SAN, and I can setup Layer 2
between the two farms.
I am concerned with split brain scenario where the two farms are
disconnected and both machines would become active.
What cluster configuration would you recommend for such an enviroment?