运行完成之后，可以到tmp目录下查看Hadoop-root目录和hsperfdata_root目录，其实hsperfdata_root是空的，不过在hadoop-root目录下有很多临时目录和文件：

[root@www.linuxidc.com /]# ls -l -R tmp/hadoop-root

tmp/hadoop-root:

总计 8

drwxr-xr-x 4 root root 4096 09-24 19:43 mapred

tmp/hadoop-root/mapred:

总计 16

drwxr-xr-x 4 root root 4096 09-24 19:43 local

drwxr-xr-x 2 root root 4096 09-25 16:32 system

tmp/hadoop-root/mapred/local:

总计 16

drwxr-xr-x 2 root root 4096 09-25 16:32 localRunner

drwxr-xr-x 3 root root 4096 09-24 19:43 taskTracker

tmp/hadoop-root/mapred/local/localRunner:

总计 8

-rw-r--r-- 1 root root 104 09-25 16:32 split.dta

tmp/hadoop-root/mapred/local/taskTracker:

总计 8

drwxr-xr-x 3 root root 4096 09-24 19:43 jobcache

tmp/hadoop-root/mapred/local/taskTracker/jobcache:

总计 8

drwxr-xr-x 10 root root 4096 09-25 16:32 job_local_0001

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001:

总计 64

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_m_000000_0

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_m_000001_0

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_m_000002_0

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_m_000003_0

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_m_000004_0

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_m_000005_0

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_m_000006_0

drwxr-xr-x 2 root root 4096 09-25 16:32 attempt_local_0001_r_000000_0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000000_0:

总计 0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000001_0:

总计 0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000002_0:

总计 0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000003_0:

总计 0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000004_0:

总计 0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000005_0:

总计 0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_m_000006_0:

总计 0

tmp/hadoop-root/mapred/local/taskTracker/jobcache/job_local_0001/attempt_local_0001_r_000000_0:

总计 0

tmp/hadoop-root/mapred/system:

总计 0如果没有使用root用户，就会出现很多问题，我想是因为权限的问题。

从root用户切换到用户shiyanjun：

[root@www.linuxidc.com /]# su shiyanjun配置认证，并通过ssh登录到127.0.0.1：

[shiyanjun@www.linuxidc.com hadoop-0.18.0]$ ssh-keygen

Generating public/private rsa key pair.

Enter file in which to save the key (/home/shiyanjun/.ssh/id_rsa):

/home/shiyanjun/.ssh/id_rsa already exists.

Overwrite (y/n)? y

Enter passphrase (empty for no passphrase):

Enter same passphrase again:

Your identification has been saved in /home/shiyanjun/.ssh/id_rsa.

Your public key has been saved in /home/shiyanjun/.ssh/id_rsa.pub.

The key fingerprint is:

76:7d:0c:8c:77:81:6c:eb:d9:7e:b2:d2:87:d0:ac:61 shiyanjun@www.linuxidc.com

[shiyanjun@www.linuxidc.com hadoop-0.18.0]$ ssh localhost

shiyanjun@localhost's password:

Last login: Wed Sep 24 16:30:17 2008这时，准备好待处理数据文件，开始运行WordCount工具：

[shiyanjun@www.linuxidc.com hadoop-0.18.0]$ bin/hadoop jar hadoop-0.18.0-examples.jar wordcount my-input my-output总是会因为创建输出目录而发生异常：

08/09/25 17:14:24 INFO jvm.JvmMetrics: Initializing JVM Metrics with processName=JobTracker, sessionId=

08/09/25 17:14:24 INFO mapred.FileInputFormat: Total input paths to process : 7

08/09/25 17:14:24 INFO mapred.FileInputFormat: Total input paths to process : 7

08/09/25 17:14:25 INFO mapred.JobClient: Running job: job_local_0001

08/09/25 17:14:25 INFO mapred.FileInputFormat: Total input paths to process : 7

08/09/25 17:14:25 INFO mapred.FileInputFormat: Total input paths to process : 7

08/09/25 17:14:25 ERROR mapred.LocalJobRunner: Mkdirs failed to create file:/home/shiyanjun/hadoop-0.18.0/my-output/_temporary

08/09/25 17:14:25 WARN mapred.LocalJobRunner: job_local_0001

java.io.IOException: The directory file:/home/shiyanjun/hadoop-0.18.0/my-output/_temporary doesnt exist

at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:148)

java.io.IOException: Job failed!

at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1113)

at org.apache.hadoop.examples.WordCount.run(WordCount.java:149)

at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)

at org.apache.hadoop.examples.WordCount.main(WordCount.java:155)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:597)

at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68)

at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139)

at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:53)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

at java.lang.reflect.Method.invoke(Method.java:597)

at org.apache.hadoop.util.RunJar.main(RunJar.java:155)

at org.apache.hadoop.mapred.JobShell.run(JobShell.java:54)

at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)

at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)

at org.apache.hadoop.mapred.JobShell.main(JobShell.java:68)

待解决...

因为刚刚接触Linux系统，对于一些配置还是不能游刃有余。有知道该如何配置的朋友，请不吝赐教，谢谢。