OpenLDAP and back_hdb: ObjectClass olcHdbConfig not present in server schema.

[O. Hartmann]

Hello,

I try to use back_hdb instead of back_bdb on all of the used DB backends 
with OlpenLDAP 2.4.11 on a FreeBSD 7.0 server.
When switching to 'backend hdb'
I get this error from LUMA when trying to acces the DB config under RDN 
cn=config:

olcDatabase={1}hdb ->

Could not display ldap entry. Reason:
ObjectClass olcHdbConfig not present in server schema.

Using bdb as backend works fine.

Can someone explain this restriction?

Thanks in advance,

Oliver