使用root用戶啟動hadoop的時候報錯：
[root@node1 ~]# su - hadoop -c start-all.sh starting namenode, logging to /app/hadoop/bin/../logs/hadoop-hadoop-namenode-node1.out 192.168.1.153: starting datanode, logging to /app/hadoop/bin/../logs/hadoop-hadoop-datanode-node3.out 192.168.1.152: starting datanode, logging to /app/hadoop/bin/../logs/hadoop-hadoop-datanode-node2.out 192.168.1.151: Address 192.168.1.151 maps to node1, but this does not map back to the address - POSSIBLE BREAK-IN ATTEMPT! 192.168.1.151: starting secondarynamenode, logging to /app/hadoop/bin/../logs/hadoop-hadoop-secondarynamenode-node1.out starting jobtracker, logging to /app/hadoop/bin/../logs/hadoop-hadoop-jobtracker-node1.out 192.168.1.152: starting tasktracker, logging to /app/hadoop/bin/../logs/hadoop-hadoop-tasktracker-node2.out 192.168.1.153: starting tasktracker, logging to /app/hadoop/bin/../logs/hadoop-hadoop-tasktracker-node3.out
解決方法：修改本機ssh_config文件
[root@node1 ~]# cat /etc/ssh/ssh_config GSSAPIAuthentication yse ----改為：----
GSSAPIAuthentication no
據說GSSAPIAuthentication的作用：是否允許使用基於GSSAPI的用戶認證。