code: private boolean hasEnoughDiskSpace(ClusterNode node) {
      int total = node.getTotal().diskGB;
      int free = node.getFree().diskGB;
      if (free < nodeReservedDiskGB) {
        if (LOG.isDebugEnabled()) {
          LOG.debug(node.getHost() + " not enough disk space." +
            " totalMB:" + total +
            " free:" + free +
            " limit:" + nodeReservedDiskGB);
        }
        return false;
      }
      return true;
    }
docs: Check if the ndoe has enough disk space to run tasks
  @param node the node to check
  @return true if the node has enough space, false otherwise