15.统计文件夹大小

查看一下du指令的说明：

[root@master ~]# hadoop fs -help du
-du [-s] [-h] <path> ... :
Show the amount of space(显示空间大小), in bytes(单位：bytes), used by the files that match the specified
file pattern. The following flags are optional:
-s  (显示文件夹的总大小，不显示子文件情况)Rather than showing the size of each individual file that matches the      
    pattern, shows the total (summary) size.                                   
-h  (换一种单位，方便显示)Formats the sizes of files in a human-readable fashion rather than a number
    of bytes.                                                                  
Note that, even without the -s option, this only shows size summaries one level
deep into a directory.
The output is in the form 
    size    name(full path)

演示：

hadoop fs -du /mz
hadoop fs -du -s -h /mz