Unable to load native-hadoop library for your platform

#HADOOP VARIABLES START

export JAVA_HOME=/home/yang/jdk1.7.0_80
export HADOOP_HOME=/home/hadoop/hadoop-2.7.2
export PATH=$PATH:$HADOOP_HOME/bin
export PATH=$PATH:$HADOOP_HOME/sbin
export HADOOP_MAPRED_HOME=$HADOOP_HOME
export HADOOP_COMMON_HOME=$HADOOP_HOME
export HADOOP_HDFS_HOME=$HADOOP_HOME
export YARN_HOME=$HADOOP_HOME
export HADOOP_COMMON_LIB_NATIVE_DIR=$HADOOP_HOME/lib/native
export HADOOP_OPTS="-Djava.library.path=$HADOOP_HOME/lib"
export HADOOP_OPTS="$HADOOP_OPTS -Djava.library.path=//home/hadoop/hadoop-2.7.2/lib/native"
#export HADOOP_OPTS=$HADOOP_OPTS:"-Djava.library.path=$HADOOP_INSTALL/lib/native"

export HADOOP_CONF_DIR=/home/hadoop/hadoop-2.7.2/etc/hadoop
#HADOOP VARIABLES END

This Line export HADOOP_OPTS="$HADOOP_OPTS -Djava.library.path=//home/hadoop/hadoop-2.7.2/lib/native"