AFD in an HA environment


First thing you need to decide if you really need a cluster with a shared filesystem/disk. Arguments against it are higher complexity and single point of failure. If you decide that you need it, have a look at DRBD (http://www.drbd.org/).

For cluster software have a look at heartbeat (http://www.linux-ha.org). Note, that you do not need pacemaker (keeps your applications running).