Unknown host error when listing with hadoop fs -ls / - linux

Question

I am new to Hadoop and trying to install Hadoop on multinode cluster on ubuntu 14.04-Server on VM. All goes well until I try to list the files within HDFS using hadoop fs -ls /
I keep getting an error:
ls: unknown host: Hadoop-Master.
Initially I thought I made some mistake in assigning the hostname but cross-checked with /etc/hosts and /etc./hostname. Hostname is listed correctly as Hadoop-Master. Removed hostname altogether. Only ip address remaining.
Another post here suggested to add two lines to .bashrc:
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
export HADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib
I tried doing that but still getting the same error.
Please find the relevant steps below along with edits based on information asked.
Check IP address of the master with ifconfig
Add to the /etc/hosts and edit the /etc/hostname to add the host name.
Add the relevant details to masters and slaves.
.bashrc File
export HADOOP_INSTALL=/usr/local/hadoop
export PIG_HOME=/usr/local/pig
export HIVE_HOME=/usr/local/Hive
export PATH=$PATH:$HADOOP_INSTALL/bin
export HADOOP_MAPRED_HOME=$HADOOP_INSTALL
export HADOOP_COMMON_HOME=$HADOOP_INSTALL
export HADOOP_HDFS_HOME=$HADOOP_INSTALL
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_INSTALL/lib/native
export HADOOP_OPTS="-Djava.library.path=$HADOOP_INSTALL/lib"
Java path
export JAVA_HOME='/usr/lib/jvm/java-7-oracle'
core-site.xml
<configuration>
<property>
<name>fs.default.name</name>
<value>hdfs:Hadoop-Master:9001</value>
</property>
</configuration>
hadoop-env.sh
export JAVA_HOME='/usr/lib/jvm/java-7-oracle'
Edit mapred-site.xml to include the hostname and change the value to no. of nodes present.
mapred-site.xml
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>2</value>
</property>
</configuration>
Edit hdfs-site.xml, changed the value to no. of data nodes present.​
hdfs-site.xml
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
<property>
<name>dfs.namenode.name.dir</name>
<value>file:/home/hduser/mydata/hdfs/namenode</value>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>file:/home/hduser/mydata/hdfs/datanode</value>
</property>
</configuration>
whoami
simplilearn
/etc/hosts
localhost 127.0.0.1
Hadoop-Master 192.168.207.132
Hadoop-Slave 192.168.207.140
/etc/hostname
Hadoop-Master

Answer 1

Changes to be made:
1. /etc/hosts file:
Change Hadoop-Master to HadoopMaster
2. /etc/hostname file:
Change Hadoop-Master to HadoopMaster
3. core-site.xml:
Change this
hdfs:Hadoop-Master:9001
to this
hdfs://HadoopMaster:9001
NOTE: Change Hadoop-Master to HadoopMaster in all nodes pointing to your IP. Change slaves and master files too.