The following commands can be used to restart NameNode and all the daemons:
NameNode can be stopped with the ./sbin /Hadoop-daemon.sh stop NameNode command. The NameNode can be started by using the ./sbin/Hadoop-daemon.sh start NameNode command.
The daemons can be stopped with the ./sbin /stop-all.sh The daemons can be started by using the ./sbin/start-all.sh command.