I am trying to load the module for openldap mdb backend which is suppose to be located in /usr/lib64/openldap but it is not there. I am trying this ldif;

dn: cn=module,cn=config

objectClass: olcModuleList

cn: module

olcModulepath: /usr/lib64/openldap

olcModuleload: back_mdb

ldapadd -Y EXTERNAL -H ldap:/// -f mod-mdb.ldif

Of course there re no back_bdb or back_hdb, do I not need to load the module first !? I am using centos 7, Thank you.