apachectl gracefulじゃ反映されません。
apachectl stop->apachectl startで。

[Mon Feb 26 15:14:05 2007] [notice] SIGHUP received.  Attempting to restart
WARNING: MaxClients of 100 would require 20 servers,
 and would exceed the ServerLimit value of 16.
 Automatically lowering MaxClients to 80.  To increase,
 please see the ServerLimit directive.
[Mon Feb 26 15:14:05 2007] [warn] WARNING: Attempt to change ServerLimit or ThreadLimit ignored during restart
[Mon Feb 26 15:14:05 2007] [notice] Apache configured -- resuming normal operations