This error comes when the address with port no you have specified in Hadoop configuration is already being used by some other process, or may be other instance of Hadoop is running in some other user,
for getting information about the ip and port no you want to know you can give command as follows
netstat –nl | grep <portno> or <ip here>
This will the processing using the specific port no or IP address. for more options with netstat type on shell netstat -- help will give you all the options .
and to check if other instance of Hadoop is running type
sudo jps
this will list all the process of Hadoop running in other users.
Step by step process :
