Since we disable fatal signal handling, we render the CoreDumpDirectory directive useless. This slide describes how to get corefiles without Apache explicitly chdir()ing into the directory. We run these as part of our /usr/local/etc/rc.d

If you want one corefile per pid:
   FreeBSD: sysctl -w kern.corefile="$ROOT/var/crash/%N.core.%U.%P
   Linux: sysctl -q -w kernel.core_uses_pid=0