code: @Override
    public void reconfigurePropertyImpl(String property, String newVal) 
      throws ReconfigurationException {
      if (property.equals("dfs.data.dir")) {
        try {
          LOG.info("Reconfigure " + property + " to " + newVal);
          this.refreshVolumes(newVal);
        } catch (Exception e) {
          throw new ReconfigurationException(property, 
          newVal, getConf().get(property), e);
        }
      } else {
        throw new ReconfigurationException(property, newVal,
                                          getConf().get(property));
      }
    }
docs: {@inheritDoc}