File README.module-loading of Package openldap2
All of the OpenLDAP backends (except back-config) and overlays are now
compiled as dynamic modules in our packages. If you want to use any of
these in your setup make sure to put the correct "olcModuleLoad" or
"moduleload" statements in your configuration.
For details please see the slapd-config(5) and slapd.conf(5) manpages
(depending on which config mechanism you use).
For a list of the included dynamic modules list all modules files:
Or just the backend files:
Documentations for the overlays can be found in the respective man pages or
the OpenLDAP Administration Guide which is part of the "openldap2-doc"
man 5 slapo-<back_name>
man 5 slapo-<name>