Asterisk HA setup w/ DRBD + drbdlinks

Can anyone recommend a good tutorial on a decent asterisk setup using FreePBX?

I have been doing a bit of research into how exactly to go about creating an Asterisk/FreePBX cluster setup. What I have found is that in order to do this correctly with DRBD, one must use the drbdlinks service to create symlinks into the shared DRBD mount point. My main problem at this point is in figuring out what all folders/files I should have in the DRBD partition and configured as symlinks.

Does anyone have any idea what all these would be, or what I am talking about here? Basically, what I need is the directory structure of all relevant configuration files and user files that would be changing during the normal course of operations.

This is what I have found so far - could anyone please add any other files/paths that I should have centralized for sharing within the cluster? Thank you very much!

link('/var/spool/asterisk') link('/var/spool/exim4') link('/var/spool/mail') link('/var/www') link('/var/lib/asterisk') link('/var/lib/munin') link('/var/lib/mysql') link('/var/lib/exim4') link('/var/lib/php5') link('/etc/asterisk') link('/etc/apache2') link('/etc/exim4') link('/etc/munin') link('/etc/php5')