[Dovecot] 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?