配置可能会随实际情况增减。尤其是有时端口冲突，导致datanode或tasktracker起不来，需求增加相应的配置。参考对应的default配置文件和手册完成。
将配置拷贝到47，46两台机器。
[@Hadoop48 hadoop-1.0.3]$ ./bin/hadoop namenode -format
12/05/23 17:04:42 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = Hadoop48/192.168.10.48
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 1.0.3
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.0 -r 1335192; compiled by ‘hortonfo’ on Tue May 8 20:31:25 UTC 2012
************************************************************/
12/05/23 17:04:42 INFO util.GSet: VM type = 64-bit
12/05/23 17:04:42 INFO util.GSet: 2% max memory = 17.77875 MB
12/05/23 17:04:42 INFO util.GSet: capacity = 2^21 = 2097152 entries
12/05/23 17:04:42 INFO util.GSet: recommended=2097152, actual=2097152
12/05/23 17:04:42 INFO namenode.FSNamesystem: fsOwner=zhouhh
12/05/23 17:04:42 INFO namenode.FSNamesystem: supergroup=supergroup
12/05/23 17:04:42 INFO namenode.FSNamesystem: isPermissionEnabled=true
12/05/23 17:04:42 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100
12/05/23 17:04:42 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
12/05/23 17:04:42 INFO namenode.NameNode: Caching file names occuring more than 10 times
12/05/23 17:04:42 INFO common.Storage: Image file of size 112 saved in 0 seconds.
12/05/23 17:04:42 INFO common.Storage: Storage directory /home/zhouhh/myhadoop/dfs/name has been successfully formatted.
12/05/23 17:04:42 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at Hadoop48/192.168.10.48
************************************************************/
因为我前面在.bashrc中加了路径和环境变量，因此，也可以直接用
[@Hadoop48 hadoop-1.0.3]$ hadoop namenode -format
该命令格式化hdfs-site.xml里面定义的dfs.name.dir路径，用于保存跟踪和协同DataNode的信息。
[@Hadoop48 ~]$ find myhadoop/
myhadoop/
myhadoop/dfs
myhadoop/dfs/name
myhadoop/dfs/name/previous.checkpoint
myhadoop/dfs/name/previous.checkpoint/fstime
myhadoop/dfs/name/previous.checkpoint/edits
myhadoop/dfs/name/previous.checkpoint/fsimage
myhadoop/dfs/name/previous.checkpoint/VERSION
myhadoop/dfs/name/image
myhadoop/dfs/name/image/fsimage
myhadoop/dfs/name/current
myhadoop/dfs/name/current/fstime
myhadoop/dfs/name/current/edits
myhadoop/dfs/name/current/fsimage
myhadoop/dfs/name/current/VERSION
[@Hadoop48 hadoop-1.0.3]$ start-dfs.sh
starting namenode, logging to /home/zhouhh/hadoop-1.0.3/libexec/../logs/hadoop-zhouhh-namenode-Hadoop48.out
Hadoop46: Bad owner or permissions on /home/zhouhh/.ssh/config
Hadoop47: Bad owner or permissions on /home/zhouhh/.ssh/config
Hadoop48: Bad owner or permissions on /home/zhouhh/.ssh/config
[@Hadoop48 .ssh]$ ls -l
total 20
-rw——- 1 zhouhh zhouhh 794 Apr 13 10:21 authorized_keys
-rw-rw-r– 1 zhouhh zhouhh 288 May 23 10:37 config
原来config文件权限不对
[@Hadoop48 .ssh]$ chmod 600 config
[@Hadoop48 .ssh]$ ls -l
total 20
-rw——- 1 zhouhh zhouhh 794 Apr 13 10:21 authorized_keys
-rw——- 1 zhouhh zhouhh 288 May 23 10:37 config
[@Hadoop48 ~]$ start-dfs.sh
starting namenode, logging to /home/zhouhh/hadoop-1.0.3/libexec/../logs/hadoop-zhouhh-namenode-Hadoop48.out
Hadoop47: bash: line 0: cd: /home/zhouhh/hadoop-1.0.3/libexec/..: No such file or directory
Hadoop47: bash: /home/zhouhh/hadoop-1.0.3/bin/hadoop-daemon.sh: No such file or directory
Hadoop46: starting datanode, logging to /home/zhouhh/hadoop-1.0.3/libexec/../logs/hadoop-zhouhh-datanode-Hadoop46.out
Hadoop48: starting secondarynamenode, logging to /home/zhouhh/hadoop-1.0.3/libexec/../logs/hadoop-zhouhh-secondarynamenode-Hadoop48.out
start-dfs.sh会启动本机NameNode 和 conf/slaves 添加的DataNode
[@Hadoop48 ~]$ ssh Hadoop47
Last login: Tue May 22 17:57:01 2012 from hadoop48
[@Hadoop47 ~]$
[@Hadoop47 hadoop-1.0.3]$ vi conf/hadoop-env.sh
配置$JAVA_HOME为正确的路径。
Hadoop46做同样处理。
[@Hadoop48 ~]$ start-dfs.sh
starting namenode, logging to /home/zhouhh/hadoop-1.0.3/libexec/../logs/hadoop-zhouhh-namenode-Hadoop48.out
Hadoop47: starting datanode, logging to /home/zhouhh/hadoop-1.0.3/libexec/../logs/hadoop-zhouhh-datanode-Hadoop47.out
Hadoop46: starting datanode, logging to /home/zhouhh/hadoop-1.0.3/libexec/../logs/hadoop-zhouhh-datanode-Hadoop46.out
Hadoop48: secondarynamenode running as process 23491. Stop it first.
HDFS已经运行成功