enabling monitoring of database

I have installed openldap and on testing the out below is given .How can i configure monitor database ? I thought it is enabled by --enable monitor

root@mailbackup:/# slaptest -v -f /etc/openldap/slapd.conf bdb_monitor_db_open: monitoring disabled; configure monitor database to enable config file testing succeeded

Installation command :

./configure --sysconfdir=/etc --with-cyrus-sasl --with-threads --with-tls --with-yielding-select --with-mp --enable-slapd --enable-slurpd --enable-cleartext --enable-bdb --enable-ldap --enable-monitor --enable-perl --enable-sql --enable-syslog --enable-spasswd