[Hadoop@node01 bin]$ ./hadoop namenode-format
13/01/30 00:59:04 INFO namenode.NameNode:STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = node01/192.168.231.131
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 0.20.2
STARTUP_MSG: build =https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20 -r 911707;compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010
************************************************************/
13/01/30 00:59:04 INFO namenode.FSNamesystem:fsOwner=hadoop,root
13/01/30 00:59:04 INFOnamenode.FSNamesystem: supergroup=supergroup
13/01/30 00:59:04 INFOnamenode.FSNamesystem: isPermissionEnabled=true
13/01/30 00:59:04 INFO common.Storage:Image file of size 96 saved in 0 seconds.
13/01/30 00:59:04 INFO common.Storage:Storage directory /tmp/hadoop-hadoop/dfs/name has been successfully formatted.
13/01/30 00:59:04 INFO namenode.NameNode:SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode atnode01/192.168.231.131
************************************************************/
10.启动守护进程
注意，在启动守护进程之前，一定要先关闭防火墙（所有的结点都要），否则datanode启动失败。
[root@node04 ~]# /etc/init.d/iptables stop
iptables: Flushing firewall rules: [ OK ]
iptables: Setting chains to policy ACCEPT:filter [ OK ]
iptables: Unloading modules: [ OK ]
最好设置开机就不启动防火墙：
[root@node01 ~]# vi /etc/sysconfig/selinux
SELINUX=disable
[hadoop@node01bin]$ ./start-all.sh
startingnamenode, logging to/home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-namenode-node01.out
node03:starting datanode, logging to/home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-datanode-node03.out
node02:starting datanode, logging to/home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-datanode-node02.out
node04:starting datanode, logging to/home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-datanode-node04.out
hadoop@node01'spassword:
node01:starting secondarynamenode, logging to/home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-secondarynamenode-node01.out
startingjobtracker, logging to/home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-jobtracker-node01.out
node03:starting tasktracker, logging to /home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-tasktracker-node03.out
node02:starting tasktracker, logging to/home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-tasktracker-node02.out
node04:starting tasktracker, logging to /home/hadoop/hadoop-0.20.2/bin/../logs/hadoop-hadoop-tasktracker-node04.out
检测守护进程启动情况：
Master结点：
[hadoop@node01 jdk1.6.0_38]$ /usr/Java/jdk1.6.0_38/bin/jps
3986 Jps
3639 NameNode
3785 SecondaryNameNode
3858 JobTracker
Slave结点（以node02为例）：
[root@node02 ~]# /usr/java/jdk1.6.0_38/bin/jps