太坑爹了，我搭建好HADOOP后执行如下命令：

[root@slave1 conf]# hadoop fs -ls

结果如下：

[root@slave1 conf]# hadoop fs -ls

12/10/15 17:07:18 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 0 time(s).

12/10/15 17:07:19 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 1 time(s).

12/10/15 17:07:20 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 2 time(s).

12/10/15 17:07:21 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 3 time(s).

12/10/15 17:07:22 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 4 time(s).

12/10/15 17:07:23 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 5 time(s).

12/10/15 17:07:24 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 6 time(s).

12/10/15 17:07:25 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 7 time(s).

12/10/15 17:07:26 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 8 time(s).

12/10/15 17:07:27 INFO ipc.Client: Retrying connect to server: master/192.168.100.11:9000. Already tried 9 time(s).

Bad connection to FS. command aborted.

在网上找了很多资料，说之前没有执行hadoop namenode -format导致的，我又执行这个命令：

[root@master conf]# hadoop namenode -format

12/10/15 17:26:52 INFO namenode.NameNode: STARTUP_MSG:

Re-format filesystem in /hadoop/hdfs/name ? (Y or N) y

Format aborted in /hadoop/hdfs/name

12/10/15 17:26:54 INFO namenode.NameNode: SHUTDOWN_MSG:

结果还是不行，后来又在网上不断找资料，说上面的输入y时要输入大写Y，我又重新执行上面的操作：

[root@master conf]# hadoop namenode -format

12/10/15 17:30:51 INFO namenode.NameNode: STARTUP_MSG:

Re-format filesystem in /hadoop/hdfs/name ? (Y or N) Y

12/10/15 17:30:54 INFO namenode.FSNamesystem: fsOwner=root,root,sfcb

12/10/15 17:30:54 INFO namenode.FSNamesystem: supergroup=supergroup

12/10/15 17:30:54 INFO namenode.FSNamesystem: isPermissionEnabled=true

12/10/15 17:30:54 INFO common.Storage: Image file of size 94 saved in 0 seconds.

12/10/15 17:30:54 INFO common.Storage: Storage directory /hadoop/hdfs/name has been successfully formatted.

12/10/15 17:30:54 INFO namenode.NameNode: SHUTDOWN_MSG:

[root@master conf]# start-all.sh

starting namenode, logging to /usr/local/hadoop/bin/../logs/hadoop-root-namenode-master.oracle.com.out

slave1: starting datanode, logging to /usr/local/hadoop/bin/../logs/hadoop-root-datanode-slave1.oracle.com.out

master: starting secondarynamenode, logging to /usr/local/hadoop/bin/../logs/hadoop-root-secondarynamenode-master.oracle.com.out

starting jobtracker, logging to /usr/local/hadoop/bin/../logs/hadoop-root-jobtracker-master.oracle.com.out

slave1: starting tasktracker, logging to /usr/local/hadoop/bin/../logs/hadoop-root-tasktracker-slave1.oracle.com.out

[root@master conf]# hadoop dfs -mkdir hadoopdir

[root@master conf]# hadoop dfs -ls // 这才整对

drwxr-xr-x - root supergroup 0 2012-10-15 17:37 /user/root/hadoopdir

[root@master conf]#

朋友们，在安装的时候一定要注意细节啊！