hadoop的几个常用命令

官方文档：http://hadoop.apache.org/docs/r1.2.1/file_system_shell.html

1、登录主节点，切换到hdfs用户

[hdfs@cdhm1~]#su - hdfs

2、列出当前目录有哪些子目录，有哪些文件

[hdfs@cdhm1 ~]$hadoop fs  -ls  /Found 2 itemsdrwxrwxrwt   - hdfs supergroup      0 2017-05-23 16:39 /tmpdrwxr-xr-x   - hdfs supergroup        02017-05-24 15:45 /user

3、在Hadoop文件系统当中，创建一个test目录

[hdfs@cdhm1 ~]$hadoop fs  -mkdir /user/hdfs/test

查看目录下有个test目录，创建成功

[hdfs@cdhm1 ~]$hadoop fs  -ls /user/hdfs/Found 4 itemsdrwx------  - hdfs supergroup0 2017-05-26 08:00 /user/hdfs/.Trashdrwxr-xr-x   - hdfs supergroup          0 2017-06-05 15:19/user/hdfs/.sparkStagingdrwx------   - hdfs supergroup          0 2017-05-24 15:46/user/hdfs/.stagingdrwxr-xr-x   - hdfs supergroup          0 2017-07-03 10:19 /user/hdfs/test

4、删除test目录

 [hdfs@cdhm1 ~]$ hadoop fs -rmr /user/hdfs/test17/07/03 10:46:06INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval =1440 minutes, Emptier interval = 0 minutes.Moved:'hdfs://cdhm1:8020/user/hdfs/test' to trash at:hdfs://cdhm1:8020/user/hdfs/.Trash/Current

再次查看test目录已经没有了

[hdfs@cdhm1 ~]$hadoop fs  -ls /user/hdfs/Found 3 itemsdrwx------   - hdfs supergroup          0 2017-07-03 10:46 /user/hdfs/.Trashdrwxr-xr-x   - hdfs supergroup          0 2017-06-05 15:19/user/hdfs/.sparkStagingdrwx------   - hdfs supergroup          0 2017-05-24 15:46/user/hdfs/.staging

5、把Hadoop文件系统当中的文件下载到本地

[hdfs@cdhm1 ~]$hadoop fs  -get /user/hdfs/test2

查看本地test2下载成功

[hdfs@cdhm1 ~]$ lstest2  test.txt

把本地文件上传到Hadoop文件系统当中

[hdfs@cdhm1 ~]$hadoop  fs  -put test.txt /user/hdfs/

查看hadoop中test.txt已成功上传

[hdfs@cdhm1 ~]$hadoop fs -ls /user/hdfs/Found 5 itemsdrwx------   - hdfs supergroup          0 2017-07-03 10:46 /user/hdfs/.Trashdrwxr-xr-x   - hdfs supergroup          0 2017-06-05 15:19/user/hdfs/.sparkStagingdrwx------   - hdfs supergroup          0 2017-05-24 15:46/user/hdfs/.staging-rw-r--r--   3 hdfs supergroup          0 2017-07-03 11:13 /user/hdfs/test.txtdrwxr-xr-x   - hdfs supergroup          0 2017-07-03 11:04 /user/hdfs/test2