I already installed Hadoop on my machine \"Ubuntu 13.05\" and now I have an error when browsing localhost:50070 the browser says that the page does not exist.
Try
namenode -format start-all.sh stop-all.sh jps
see namenode and datanode are running and browse
namenode
datanode
localhost:50070
If localhost:50070 is still not working, then you need to allows ports. So, check
netstat -anp | grep 50070