when I check cluster health, I get following error message from time to time, Could anyone help on it?   The health test result for NAME_NODE_DIRECTORY_FAILURES has become unknown: Not enough data to test: Test of whether the NameNode has directory failures. The health test result for NAME_NODE_SAFE_MODE has become unknown: Not enough data to test: Test of whether the NameNode is in safe mode. The health test result for NAME_NODE_UPGRADE_STATUS has become unknown: Not enough data to test: Test of whether there is an unfinalized HDFS metadata upgrade. The health test result for NAME_NODE_LOG_DIRECTORY_FREE_SPACE has become unknown: Not enough data to test: Test of whether this role's log directory has enough free space. The health test result for NAME_NODE_HEAP_DUMP_DIRECTORY_FREE_SPACE has become unknown: Not enough data to test: Test of whether this role's heap dump directory has enough free space. The health test result for NAME_NODE_DATA_DIRECTORIES_FREE_SPACE has become unknown: Not enough data to test: Test of whether the NameNode Data Directories have enough free space. The health test result for HOST_SCM_HEALTH has become bad: This host is in contact with the Cloudera Manager Server. This host is not in contact with the Host Monitor. The health test result for HOST_AGENT_LOG_DIRECTORY_FREE_SPACE has become unknown: Not enough data to test: Test of whether the Cloudera Manager Agent's log directory has enough free space. The health test result for HOST_AGENT_PARCEL_DIRECTORY_FREE_SPACE has become unknown: Not enough data to test: Test of whether the Cloudera Manager Agent's parcel directory has enough free space. The health test result for HOST_AGENT_PROCESS_DIRECTORY_FREE_SPACE has become unknown: Not enough data to test: Test of whether the Cloudera Manager Agent's process directory has enough free space. ... View more