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#

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)

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

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

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

hadoop namenode -format