当我们执行hadoop fs -put aa.txt /bb.txt,则aa.txt会被复制为集群的/bb.txt。查看系统的log日志hadoop-$username-namenode-*.log,可以看到类似于
2011-09-07 08:39:12,506 INFO org.apache.hadoop.hdfs.StateChange: BLOCK* NameSystem.addStoredBlock: blockMap updated: 127.
0.0.1:50010 is added to blk_5715489406767973176_1455 size 32
这样的信息,里面记录有分配block的元数据信息和block号(blk_5715489406767973176)。
在另一个日志中hadoop-$username-datanode-*.log可以看到对应的datanode打印出相应的log:
2011-09-07 08:39:12,495 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Receiving block blk_5715489406767973176_145
5 src: /127.0.0.1:48492 dest: /127.0.0.1:50010