执行slapcat 出现如下错误，启动slapd服务也失败
qisen@jdcloud:/var/lib/ldap$ sudo slapcat 579f099a hdb_db_open: database "dc=phoneos,dc=org": unclean shutdown detected; attempting recovery. 579f099a hdb_db_open: database "dc=phoneos,dc=org": recovery skipped in read-only mode. Run manual recovery if errors are encountered. 579f099a bdb(dc=phoneos,dc=org): BDB1538 Program version 5.3 doesn't match environment version 5.1 579f099a hdb_db_open: database "dc=phoneos,dc=org" cannot be opened, err -30969. Restore from backup! 579f099a backend_startup_one (type=hdb, suffix="dc=phoneos,dc=org"): bi_db_open failed! (-30969) slap_startup failed
Program version 5.3 doesn't match environment version 5.1 主要根据这句，猜想是数据库格式问题，所以安装 bdb5.1
sudo apt-get install db5.1-util
然后通过如下命令，修复数据库：
db5.1_checkpoint -1 db5.1_recover
修复后，再之执行slapcat，成功。sudo service slapd start 正常启动。