HDFS 報錯： There are 0 datanode(s) running and 0 node(s) are excluded in this operation.

解決方法1：重啟linux,再使用start-dfs.sh和start-yarn.sh 重啟壹下hadoop

解決辦法2：找到hadoop安裝目錄下 hadoop-2.4.1/data/dfs/data裏面的current文件夾刪除

然後從新執行壹下 hadoop namenode -format

再使用start-dfs.sh和start-yarn.sh 重啟壹下hadoop