格式化hdfs 的时候报错

java.io.FileNotFoundException: master (No such file or directory)
	at java.io.FileInputStream.open0(Native Method)
	at java.io.FileInputStream.open(FileInputStream.java:195)
	at java.io.FileInputStream.<init>(FileInputStream.java:138)
	at org.apache.hadoop.util.HostsFileReader.readFileToSet(HostsFileReader.java:65)
	at org.apache.hadoop.hdfs.server.blockmanagement.HostFileManager.readFile(HostFileManager.java:72)
	at org.apache.hadoop.hdfs.server.blockmanagement.HostFileManager.refresh(HostFileManager.java:137)
	at org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager.<init>(DatanodeManager.java:201)
	at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager.<init>(BlockManager.java:288)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.<init>(FSNamesystem.java:825)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.<init>(FSNamesystem.java:783)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.format(NameNode.java:1034)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1479)
	at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1606)

答：这是参数配置错误导致的在hdfs-site.xml中配置dfs.hosts 参数的值应该是写有hostname的文件路径而不是 hostname。

<property>
        <name>dfs.hosts</name>
        <value>master</value>
        <describe>datanode-list-file-path some file like slaves </describe>
    </property>