解决There are 0 datanode(s) running and no node(s) are excluded in this operation.
出现上述问题可能是格式化两次hadoop,导致没有datanode解决方法1:重启linux,再使用start-dfs.sh和start-yarn.sh重启一下hadoop解决办法2:找到hadoop安装目录下hadoop-2.4.1/data/dfs/data里面的current文件夹删除然后从新执行一下hadoopnamenode-format再使用start-dfs.sh和start-yar