Quiz timouts in moodle adjusting session lifetime

I had a customer call me last night and say that two of his students just finished a 2 + hr exam, submitted their work and lost it.  Upon a bit more investigation, I found that the moodle session had silently timed out while they were taking their quiz.  My first thought was "huh, would'nt the quiz activity, kids typing in data in questions and clicking on radio buttons, keep the session active?". 

The answer is no.

Yikes.  Data lose is a big problem.

I read through this moodle forum to gain a little more perspective, and ended up changing my session timout in the moodle server from 2 to 6 hrs.  We have some quizzes that are up to 6 hrs long.  I am not crazy about this increase, but it seems necessary to avoid the problem of students taking very long exams and then getting timed out.

Steps to change the moodle session timeout.

1 - Update the php.ini file.  Updating the session.gc_maxlife setting from 12200 to 30500 and restarted apache
2 - Browsed to Site Admin | Server | Session handling | Timeout
     changed the timeout value to 4 hrs.