ubuntu安装Hadoop是出现
The authenticity of host ‘0.0.0.0 (0.0.0.0)’ can’t be established.（错误），
代码如下：
root@master:/usr/local/hadoop/hadoop-2.6.0# sbin/start-dfs.sh
Starting namenodes on [localhost]
localhost: starting namenode, logging to /usr/local/hadoop/hadoop-2.6.0/logs/hadoop-root-namenode-master.out
localhost: starting datanode, logging to /usr/local/hadoop/hadoop-2.6.0/logs/hadoop-root-datanode-master.out
Starting secondary namenodes [0.0.0.0]
The authenticity of host '0.0.0.0 (0.0.0.0)' can't be established. ECDSA key fingerprint is dc:f6:ec:22:ca:5c:5d:b2:e1:cb:0f:77:ce:f9:57:07. Are you sure you want to continue connecting (yes/no)? ^C0.0.0.0: Host key verification failed. 解决方法：关闭防火墙
执行命令:
root@master:# ufw disable