（Hadoop datanode 有关问题）There are 0 datanode(s) running and no node(s) are excluded in this operation
（Hadoop datanode 问题）There are 0 datanode(s) running and no node(s) are excluded in this operation
这是一个版本残留问题，
删除dfs.namenode.name.dir设置的（file：///dfs/data）目录下的current 文件夹即可解决。