Namenode is not starting, errors encountered

[#1]

I am very new to this field. I am installing hortonworks 2.6 on centos6. Everything is going fine but namenode is not starting. I am attaching picture of namenode errors. Please help

[#2]

@Shital L

Are all the other services up?

If it's not an HA setup can you run the following command on the NameNode host machine

su -l hdfs -c "/usr/hdp/current/hadoop-hdfs-namenode/../hadoop/sbin/hadoop-daemon.sh start namenode"

Please revert