Sync Freepbx to a standby server

Is there a way to sync freepbx to a standby server? Keeping the database in sync is easy enough but how do you keep Freepbx in sync between the two servers? I can do an rsync of /etc/asterisk and /var/www/html but the freepbx on the standby server complains about broken modules. Am I missing a directory to sync? Any way to automate freepbx updates so they are applied to both servers automatically?