Hadoop 2.x 快照

时间:2014-12-02 15:47 来源:linux.it.net.cn 作者:IT

在2.x 终于实现了快照
设置一个目录为可快照:

1	hdfs dfsadmin -allowSnapshot <path>

1	hdfs dfsadmin -disallowSnapshot <path>

生成快照

1	hdfs dfs -createSnapshot <path> [<snapshotName>]

删除快照

1	hdfs dfs -deleteSnapshot <path> <snapshotName>

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[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfsadmin -allowSnapshot /
Allowing snaphot on / succeeded
[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfs -put ../test1.txt /test1.txt
[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfs -ls /
Found 1 items
-rw-r--r-- 1 hadoop supergroup       12 2014-08-31 23:26 /test1.txt
[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfs -createSnapshot /
Created snapshot /.snapshot/s20140831-232654.464
[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfs -ls /.snapshot
Found 2 items
drwxr-xr-x - hadoop supergroup       0 2014-08-31 23:24 /.snapshot/s20140831-232445.185
drwxr-xr-x - hadoop supergroup       0 2014-08-31 23:26 /.snapshot/s20140831-232654.464

#恢复快照
[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfs -mkdir /tmp
[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfs -cp /.snapshot/s20140831-232654.464 /tmp
[hadoop@hadoop1 hadoop-2.5.0]$ ./bin/hdfs dfs -cat /tmp/s20140831-232654.464/test1.txt
hello world

其他快照操作

列出所有可快照目录

1	hdfs lsSnapshottableDir

比较快照直接的差异

1	hdfs snapshotDiff <path> <fromSnapshot> <toSnapshot>

(责任编辑：IT)