You generally should start with an aureport over the time period you saw
the issue, then drill down from there. But if your audit logs are not
larger than usual maybe this isn't your problem.
What symptoms of struggling are you seeing? You said top shows nothing
out of the ordinary and no directories are getting full (I suppose you
mean /var/log/audit)...so I am not certain what behavior you see that is
leading you towards audit being the problem.
LCB
--
LC (Lenny) Bruzenak
lenny(a)magitekltd.com