In addition you have to keep an eye on sessions. Either the load balancer supports sticky sessions or you delegate the session handling to the database.
Of course there is this 'moodledata' ($CFG->dataroot
) to which both servers need to have access, you knew that I believe. If not, make use of the 'Advanced search' linked to the intro to this forum.
If you are new, get each server working alone, i.e. without a load balancer, and then try to couple them.
P.S. You shoule leave a note in the "Installation problems" forum https://moodle.org/mod/forum/discuss.php?d=216576
pointing to this discussion as the follow-up. Ideally that discussion should have been moved here. I know, the site moderators are reluctant to do that fearing that might upset the posters. May be this Alice quote will help: http://ebooks.adelaide.edu.au/c/carroll/lewis/alice/chapter12.html#chapter12