[b0002] Hadoop HDFS cmd常用命令練手

目的：

學會HDFS CLI 常用操作

環境：

Hadoop 2.6.4 偽分布式版

環境搭建參考本博客前篇文章：

偽分布式 hadoop 2.6.4

幫助:

hadoop@ssmaster:~$ hadoop fs
Usage: hadoop fs [generic options]
    [-appendToFile <localsrc> ... <dst>]
    [-cat [-ignoreCrc] <src> ...]
    [-checksum <src> ...]
    [-chgrp [-R] GROUP PATH...]
    [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...]
    [-chown [-R] [OWNER][:[GROUP]] PATH...]
    [-copyFromLocal [-f] [-p] [-l] <localsrc> ... <dst>]
    [-copyToLocal [-p] [-ignoreCrc] [-crc] <src> ... <localdst>]
    [-count [-q] [-h] <path> ...]
    [-cp [-f] [-p | -p[topax]] <src> ... <dst>]
    [-createSnapshot <snapshotDir> [<snapshotName>]]
    [-deleteSnapshot <snapshotDir> <snapshotName>]
    [-df [-h] [<path> ...]]
   .........
   .........

任務：

1  創建目錄

hadoop@ssmaster:~$ hadoop fs -mkdir data
hadoop@ssmaster:~$ hadoop fs -ls /
Found 1 items
drwxr-xr-x - hadoop supergroup 0 2016-10-22 22:33 /data

2  Linux 本地准備文件,內容任意英文

hadoop@ssmaster:~$ vi paper.txt
hadoop@ssmaster:~$ ls
Desktop  Documents  Downloads  examples.desktop  hadoop-2.6.4.tar.gz  Music  paper.txt  Pictures  Public  Templates  Videos
hadoop@ssmaster:~$ more paper.txt

There are moments in life when you miss someone so much that you just want to pick them from your dreams and hug them for real! Dream
what you want to dream;go where you want to go;be what you want to be,because you have only one life and one chance to do all the th
ings you want to do

.....

3  上傳文件 Linux 本地到 HDFS

hadoop@ssmaster:~$ hadoop fs -put paper.txt /data
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.

hadoop@ssmaster:~$ hadoop fs -ls /data
Found 1 items
-rw-r--r--   1 hadoop supergroup       1762 2016-10-22 22:44 /data/paper.txt

4  查看HDFS 文件內容

hadoop@ssmaster:~$ hadoop fs -cat /data/paper.txt
There are moments in life when you miss someone so much that you just want to pick them from your dreams and hug them for real! Dream what you want to dream;go where you want to go;be what you want to be,because you have only one life and one chance to do all the things you want to do.

5 下載到linux本地

hadoop@ssmaster:~$ rm paper.txt 
hadoop@ssmaster:~$ ls
Desktop  Documents  Downloads  examples.desktop  hadoop-2.6.4.tar.gz  Music  Pictures  Public  Templates  Videos
hadoop@ssmaster:~$ hadoop fs -get /data/paper.txt
hadoop@ssmaster:~$ ls
Desktop  Documents  Downloads  examples.desktop  hadoop-2.6.4.tar.gz  Music  paper.txt  Pictures  Public  Templates  Videos

6  刪除HDFS 文件

hadoop@ssmaster:~$ hadoop fs -rm /data/paper.txt
16/10/22 22:47:28 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 0 minutes, Emptier interval = 0 minutes.
Deleted /data/paper.tx

 

7 刪除目錄

hadoop@ssmaster:~$ hadoop fs -ls /
Found 4 items
drwxr-xr-x   - hadoop supergroup          0 2016-10-22 22:48 /data
drwxr-xr-x   - hadoop supergroup          0 2016-10-23 00:01 /input
drwxr-xr-x   - hadoop supergroup          0 2016-10-23 00:08 /output
drwx------   - hadoop supergroup          0 2016-10-23 00:05 /tmp

hadoop@ssmaster:~$ hadoop fs -rm  -r /input
16/10/23 00:37:03 INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 0 minutes, Emptier interval = 0 minutes.
Deleted /input
hadoop@ssmaster:~$ hadoop fs -ls /
Found 3 items
drwxr-xr-x   - hadoop supergroup          0 2016-10-22 22:48 /data
drwxr-xr-x   - hadoop supergroup          0 2016-10-23 00:08 /output
drwx------   - hadoop supergroup          0 2016-10-23 00:05 /tmp