启动失败-dfs.sh:

nikita@master:/usr/local/hadoop/sbin$ ./start-dfs.sh

Starting namenodes on [master]
ERROR: namenode can only be executed by root.
Starting datanodes
ERROR: datanode can only be executed by root.
Starting secondary namenodes [master]
ERROR: secondarynamenode can only be executed by root.

nikita@master:/usr/local/hadoop/sbin$ sudo ./start-dfs.sh

Starting namenodes on [master]
master: Permission denied (publickey,password).
Starting datanodes
localhost: Permission denied (publickey,password).
Starting secondary namenodes [master]
master: Permission denied (publickey,password).

运行“ssh master”-ok；运行“sudo ssh master”-权限被拒绝
如何解决？没有sudo如何运行start-dfs.sh？