Linux下快速删除大量小文件（HP-UX也适用）

大侠们是否删除百万千万级甚至更多的小文件吧，用rm -rf  命令非常慢，极度挑战人类的耐性。这时可用rsync工具删除，测试过Linux和HP-UX都可以用。

先确定操作系统是否装好rsync，HP-UX默认未装rsync，到http://hpux.connect.org.uk/搜索rsync包下载安装即可，记得先装依赖包。

rsync使用的是替换原理。

1、创建一个空目录

-bash-4.3#
mkdir /mnt/empt

2、使用rsync同步删除

注意：目录后面加上“/” ，/mnt/many/100w/是要删除的目录

-bash-4.3#
rsync --delete-before -a -H -v --progress --stats /mnt/empty /mnt/many/100w/
....

deleting 1W94.3MB/300029.63MB/Lib/__future__.py

.....

Number of files: 1 (dir: 1)

Number of created files: 0

Number of deleted files: 105,720 (reg: 100,000, dir: 5,720)

Number of regular files transferred: 0

Total file size: 0 bytes

Total transferred file size: 0 bytes

Literal data: 0 bytes

Matched data: 0 bytes

File list size: 0

File list generation time: 0.001 seconds

File list transfer time: 0.000 seconds

Total bytes sent: 46

Total bytes received: 6,339,527

sent 46 bytes  received 6,339,527 bytes  7,605.97 bytes/sec

total size is 0  speedup is 0.00

选项说明：
--delete-before 接收者在传输之前进行删除操作
-a 归档模式，表示以递归方式传输文件，并保持所有文件属性
-H 保持硬连接的文件
-v 详细输出模式
--progress 在传输时显示传输过程

--stats 给出某些文件的传输状态
一般不需要显示进度，使用以下命令即可：
-bash-4.3#
rsync --delete-before -a -H /mnt/empty /mnt/many/100w/

删除完后只剩下/mnt/many/100w/空目录，里面的文件都被删除。

3、rsync一些跟删除有关的参数

-bash-4.3# rsync --help | grep delete
     --del                   an alias for --delete-during

     --delete                delete extraneous files from destination dirs

     --delete-before         receiver deletes before transfer, not during

     --delete-during         receiver deletes during the transfer

     --delete-delay          find deletions during, delete after

     --delete-after          receiver deletes after transfer, not during

     --delete-excluded       also delete excluded files from destination dirs

     --delete-missing-args   delete missing source args from destination

     --ignore-errors         delete even if there are I/O errors

     --max-delete=NUM        don't delete more than NUM files