Hadoop啟動HDFS程序的時候報錯，提示權限不夠，具體資訊如圖所示：
localhost: frankxulei@localhost: Permission denied (publickey,password).
frankxulei@ubuntu:/usr/local/hadoop$ sbin/start-all.sh
WARNING: Attempting to start all Apache Hadoop daemons as frankxulei in 10 seconds.
WARNING: This is not a recommended production deployment configuration.
WARNING: Use CTRL-C to abort.
Starting namenodes on [localhost]
Starting datanodes
Starting secondary namenodes [ubuntu]
ubuntu: frankxulei@ubuntu: Permission denied (publickey,password).
Starting resourcemanager
Starting nodemanagers
frankxulei@ubuntu:/usr/local/hadoop$
解決辦法，複制導入公鑰就可以了，SSH連結需要使用公鑰認證：
切換到ssh目錄：cd ~/.ssh/
ssh-keygen -t rsa -P ""
cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys 
再次啟動HDFS就可以了，
sbin/start-dfs.sh