--- fixes: - | Fixes database schema that could cause the wrong database engine to be utilized for the ``conductor_hardware_interfaces`` table, if the system is using MySQL prior to version 5.5 or the ``default_storage_engine`` option is set explicitly to 'MyISAM' in ``my.cnf``. In this case, a table could be created with MyISAM engine, and the foreign key constraint ``conductor_id(conductors.id)`` was ignored. See `bug 1702158 `_ for details. upgrade: - | Due to `bug 1702158 `_, the ``conductor_hardware_interfaces`` table could be created with MyISAM database engine, while all other tables in ironic database are using InnoDB engine. This could happen during initial installation, or upgrade to the Ocata release, if the system was using MySQL prior to version 5.5 or the ``default_storage_engine`` option was set explicitly to 'MyISAM' in ``my.cnf``. If this is the case, the ``conductor_hardware_interfaces`` table needs to be manually migrated to InnoDB, and the foreign key constraint needs to be re-created:: alter table conductor_hardware_interfaces engine='InnoDB'; alter table conductor_hardware_interfaces add constraint conductor_hardware_interfaces_ibfk_1 foreign key (conductor_id) references conductors(id);