环境
hadoop:0.20.205.0
群集中的计算机数：2个节点
复制：设置为1
dfs块大小：1mb
我使用put命令将一个7.4mb的文件放入hdfs。我运行fsck命令来检查文件在datanodes之间的块分布。我看到文件的所有8个块都只指向一个节点。这会影响负载分布，并且在运行Map任务时，始终只使用一个节点。
有没有一种方法可以将文件分发到多个datanode？

bin/hadoop dfsadmin -report
Configured Capacity: 4621738717184 (4.2 TB)
Present Capacity: 2008281120783 (1.83 TB)
DFS Remaining: 2008281063424 (1.83 TB)
DFS Used: 57359 (56.01 KB)
DFS Used%: 0%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0

-------------------------------------------------
Datanodes available: 2 (6 total, 4 dead)

Name: 143.215.131.246:50010
Decommission Status : Normal
Configured Capacity: 2953506713600 (2.69 TB)
DFS Used: 28687 (28.01 KB)
Non DFS Used: 1022723801073 (952.49 GB)
DFS Remaining: 1930782883840(1.76 TB)
DFS Used%: 0%
DFS Remaining%: 65.37%
Last contact: Fri Jul 18 10:31:51 EDT 2014

bin/hadoop fs -put /scratch/rkannan3/hadoop/test/pg20417.txt /user/rkannan3

bin/hadoop fs -ls /user/rkannan3
Found 1 items
-rw-------   1 rkannan3 supergroup    7420270 2014-07-18 10:40 /user/rkannan3/pg20417.txt

bin/hadoop fsck /user/rkannan3 -files -blocks -locations
FSCK started by rkannan3 from /143.215.131.246 for path /user/rkannan3 at Fri Jul 18 10:43:13 EDT 2014
/user/rkannan3 <dir>
/user/rkannan3/pg20417.txt 7420270 bytes, 8 block(s):  OK <==== All the 8 blocks in one DN
0. blk_3659272467883498791_1006 len=1048576 repl=1 [143.215.131.246:50010]
1. blk_-5158259524162513462_1006 len=1048576 repl=1 [143.215.131.246:50010]
2. blk_8006160220823587653_1006 len=1048576 repl=1 [143.215.131.246:50010]
3. blk_4541732328753786064_1006 len=1048576 repl=1 [143.215.131.246:50010]
4. blk_-3236307221351862057_1006 len=1048576 repl=1 [143.215.131.246:50010]
5. blk_-6853392225410344145_1006 len=1048576 repl=1 [143.215.131.246:50010]
6. blk_-2293710893046611429_1006 len=1048576 repl=1 [143.215.131.246:50010]
7. blk_-1502992715991891710_1006 len=80238 repl=1 [143.215.131.246:50010]