From: Cameron Smith on
I am currently using Heartbeat to manage http, mysql and a DRBD device
between two nodes.

I want to also manage Postfix for server messages and user mail services
with Heartbeat so that if node one goes down that mail services continue
seamlessly on node two. I am aware of how to put data that needs to go
across on the DRBD device so that part of the functionality I understand.

What things should I keep in mind in the configuration of Postfix itself so
that mail services are tied to the IP managed by Heartbeat rather then the
IP's of each node

Are there any unique things regarding HA and an MTA I should be aware of
when setting this up?

What to do in terms of the hostname for mail services from one node to the
other?

How do I handle server mail messages on the secondary node when the HA
managed Postfix is down?

Thank you,
Cameron