hi, am working on my ldap server. it was ok until 2 hours ago but now, ldapsearch doesn't run. this is the output on syslog: @(#) $OpenLDAP: slapd 2.4.23 (Jun 16 2011 02:53:39) $#012#011buildd@murphy:/build/buildd-openldap_2.4.23-7.2-i386-Y1mwvF/openldap-2.4.23/debian/build/servers/slapd Mar 26 16:11:33 amahoro slapd[1604]: hdb_db_open: database "dc=amahoro,dc=bi" cannot be opened, err 13. Restore from backup! Mar 26 16:11:33 amahoro slapd[1604]: bdb(dc=amahoro,dc=bi): txn_checkpoint interface requires an environment configured for the transaction subsystem Mar 26 16:11:33 amahoro slapd[1604]: bdb_db_close: database "dc=amahoro,dc=bi": txn_checkpoint failed: Invalid argument (22). Mar 26 16:11:33 amahoro slapd[1604]: backend_startup_one (type=hdb, suffix="dc=amahoro,dc=bi"): bi_db_open failed! (13) Mar 26 16:11:33 amahoro slapd[1604]: bdb_db_close: database "dc=amahoro,dc=bi": alock_close failed Mar 26 16:11:33 amahoro slapd[1604]: slapd stopped. what is the problem?