我试着在香蕉皮上运行hadoop，我不明白为什么我的hadoop不起作用。
我在运行非常基本的命令时遇到了一个异常

root@bananapi:/opt/hadoop# hadoop fs -ls
14/12/17 10:27:13 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your     platform... using builtin-java classes where applicable
ls: Call From bananapi/10.0.2.150 to localhost:9000 failed on connection exception:        
java.net.ConnectException: Connection refused; For more details see:      http://wiki.apache.org/hadoop/ConnectionRefused
root@bananapi:/opt/hadoop#

我已经安装了以下jdk

root@bananapi:/opt/hadoop# java -version
java version "1.7.0_65"
OpenJDK Runtime Environment (IcedTea 2.5.3) (7u71-2.5.3-2~deb7u1)
OpenJDK Zero VM (build 24.65-b04, mixed mode)

我的etc/hosts文件如下所示：

root@bananapi:/opt/hadoop# cat /etc/hosts
127.0.0.1   localhost
10.0.2.150  bananapi  # wlan0
10.0.2.119  bananapi  # eth0
::1     localhost ip6-localhost ip6-loopback
fe00::0     ip6-localnet
ff00::0     ip6-mcastprefix
ff02::1     ip6-allnodes
ff02::2     ip6-allrouters

服务（jps）也在运行：

root@bananapi:/opt/hadoop# jps
3732 NodeManager
3317 NameNode
3644 ResourceManager
3401 DataNode
3513 SecondaryNameNode
3860 Jps

我做错了什么？为什么命令不起作用？
p、 我也试过跑步 hdfs dfs -ls ###更新
core-site.xml中的我的conf

<property>
  <name>fs.default.name</name>
  <value>hdfs://localhost:9000</value>
</property>

我也不能格式化namenode

hadoop namenode -format