hadoop Yarn 搭建集群时错误 主节点 NameNode 没有启动成功

执行start-dfs.sh

发现namenode没有启动成功，查看日志后发现如下错误

2016-01-17 14:32:11,562 INFO org.apache.hadoop.util.GSet: Computing capacity for map NameNodeRetryCache

2016-01-17 14:32:11,562 INFO org.apache.hadoop.util.GSet: VM type       = 32-bit
2016-01-17 14:32:11,562 INFO org.apache.hadoop.util.GSet: 0.029999999329447746% max memory 966.7 MB = 297.0 KB
2016-01-17 14:32:11,562 INFO org.apache.hadoop.util.GSet: capacity      = 2^16 = 65536 entries
2016-01-17 14:32:11,636 INFO org.apache.hadoop.hdfs.server.common.Storage: Lock on /data/hadoop/storage/hdfs/name/in_use.lock acquired by nodename 3068@samsung
2016-01-17 14:32:11,641 WARN org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Encountered exception loading fsimage

java.io.IOException: NameNode is not formatted.

由此可以看出，没有事先格式化namenode

执行: hdfs namenode -format

作用: 生成新的current/VERSION信息，此时datanode和namenode将会匹配成功