I don't get any information in my log file for openldap on my Centos 6 server. This is how i configured it. SELinux is disabled at the moment.
First created a folder where I'd like to store the log files.
mkdir /var/log/slapd chmod 755 /var/log/slapd/ chown ldap:ldap /var/log/slapd/
Then did the configuration.
ldapsearch -D "cn=admin,cn=config" -w secret -b cn=config cn=config dn: cn=config changetype:modify replace: olcLogFile olcLogFile: /var/log/slapd/slapd.log - replace: olcLogLevel olcLogLevel: conns filter config acl stats shell EOF
Just to be safe I restarted the service
service openldap restart
It does create the file, but don't write anything into the file. Of course I did some searches and updates to the LDAP-server, so it gets connections and stuff to log.
$ ls -alh total 12K drwxr-xr-x. 2 ldap ldap 4.0K Oct 25 14:27 . drwxr-xr-x. 6 root root 4.0K Oct 25 14:10 .. -rw-r--r--. 1 ldap ldap 0 Oct 25 14:33 slapd.log
My LDAP-setup can be found here (now slightly modified on my own server)