private String getHdfsDir() {
    String[] hdfsIps = TSFileDescriptor.getInstance().getConfig().getHdfsIp();
    String hdfsDir = "hdfs://";
    if (hdfsIps.length > 1) {
      hdfsDir += TSFileDescriptor.getInstance().getConfig().getDfsNameServices();
    } else {
      hdfsDir += hdfsIps[0] + ":" + TSFileDescriptor.getInstance().getConfig().getHdfsPort();
    }
    return hdfsDir;
  }
if the folders are relative paths, add IOTDB_DATA_HOME as the path prefix
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java