FSNamesystem: Not able to place enough replicas, still in need of 1

2013-07-04 01:21:50,677 WARN org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Not able to place enough replicas, still in need of 1
2013-07-04 01:21:50,677 ERROR org.apache.hadoop.security.UserGroupInformation: PriviledgedActionException as:root cause:java.io.IOException: File /share/mapreduce-streaming/core-3.1.1.jar could only be replicated to 0 nodes, instead of 1
2013-07-04 01:21:50,691 INFO org.apache.hadoop.ipc.Server: IPC Server handler 3 on 9000, call addBlock(/share/mapreduce-streaming/core-3.1.1.jar, DFSClient_NONMAPREDUCE_1542993451_1, null) from 127.0.0.1:33308: error: java.io.IOException: File /share/mapreduce-streaming/core-3.1.1.jar could only be replicated to 0 nodes, instead of 1
java.io.IOException: File /share/mapreduce-streaming/core-3.1.1.jar could only be replicated to 0 nodes, instead of 1
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:1639)
at org.apache.hadoop.hdfs.server.namenode.NameNode.addBlock(NameNode.java:736)
at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:578)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1393)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1389)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1149)

at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1387)

hadoop向dfs系统上put文件的时候，报这个错误，试过几次namenode的format，问题一直都存在，放小的文件put是没有问题了，一旦文件多了或者大的时候就出现了这个问题了，后来用df命令查看linux的空间大小，如下图：

发现根目录下面已经没有空间了，原来是空间不足的原因。空间最大的是在/home下面。

解决方法是：更改dfs的hadoop.tmp.dir路径。在core-site.xml文件里面修改的信息如下：

<property>
        <name>hadoop.tmp.dir</name>
        <value>/home/dfs</value>
        <description>A base for other temporary directories.</description>
</property>

执行stop-all.sh关闭hadoop，

格式化namenode ：hadoop namenode -format

执行start-all.sh重新启动hadoop,重新put，没有问题了。