Hadoop回收站trash

Hadoop回收站trash，默认是关闭的。 

1.修改conf/core-site.xml,增加 

 <property>
   <name>fs.trash.interval</name>
   <value>1440</value>
   <description>Number of minutes between trash checkpoints.
   If zero, the trash feature is disabled.
   </description>
 </property>

默认是0.单位分钟。这里我设置的是1天（60*24） 
删除数据rm后，会将数据move到当前文件夹下的.Trash目录 

2.测试  
1）新建目录input 

 hadoop/bin/hadoop fs -mkdir input

2）上传文件 

 root@master:/data/soft# hadoop/bin/hadoop fs -copyFromLocal /data/soft/file0* input

3）删除目录input 

 [root@master data]# hadoop fs -rmr input
 Moved to trash: hdfs://master:9000/user/root/input

4）参看当前目录 

 [root@master data]# hadoop fs -ls
 Found 2 items
 drwxr-xr-x   - root supergroup          0 2011-02-12 22:17 /user/root/.Trash

发现input删除，多了一个目录.Trash 

5）恢复刚刚删除的目录 

 [root@master data]# hadoop fs -mv /user/root/.Trash/Current/user/root/input  /user/root/input

6）检查恢复的数据 

 [root@master data]# hadoop fs -ls input
 Found 2 items
 -rw-r--r--   3 root supergroup         22 2011-02-12 17:40 /user/root/input/file01
 -rw-r--r--   3 root supergroup         28 2011-02-12 17:40 /user/root/input/file02

6）删除.Trash目录（清理垃圾） 

 [root@master data]# hadoop fs -rmr .Trash
 Deleted hdfs://master:9000/user/root/.Trash

原文：http://running.iteye.com/blog/904536