MDB_MAP_FULL: Environment mapsize limit reached

[Aleksander DzierÅanowski <olo@e-lista.pl>]

Hello OpenLDAP guru & fans.

Recently I was trying to migrate from 'bdb' to 'mdb' backend by adding
temporary additional instance of OpenLDAP. Unfortunately I'm unable to
import database both using 'slapadd' or regular replication mechanism. 
What I got is exact same error:

slapadd -b o=mysuffix < /tmp/mysuffix.ldif
5332ec95 => mdb_idl_insert_keys: c_put id failed: MDB_MAP_FULL: 
Environment mapsize limit reached (-30792)
5332ec95 => mdb_tool_entry_put: index_entry_add failed: err=80
5332ec95 => mdb_tool_entry_put: txn_aborted! Internal error (80)
slapadd: could not add entry 
dn="uid=myuser,ou=People,ou=developers,o=suffix" (line=2080): 
txn_aborted! Internal error (80)
_#                      9.26% eta   none elapsed            none spd 
2.3 M/s
Closing DB...

My bdb 'maxsize' argument is set to 1GB. Database is really small, it 
contain just few hundred of small entries. My OpenLDAP version is 2.4.38 
from OpenLTB project (I'm unable to use 2.4.39 because I need to use 
CentOS 6.4 version, latest one is for 6.5).

Changing only backend to 'bdb' in configuration make import succesfull.

Any advices?

regards,
--
Aleksander