start-dfs.sh提示rcmd: socket: Permission denied

在Ubuntu16.10上安装hadoop-3.0.0-alpha2之后,执行sbin/start-dfs.sh时提示错误"rcmd: socket: Permission denied",使用sudo则又提示"there is no HDFS_NAMENODE_USER defined",如下图所示:   解决方法: 在/etc/pdsh下面新建文件rcmd_default,写入ssh […]