HDFS

Hadoop Distributed File System: hadoop分布式文件系统

hadoop hdfs分为三部分:

NameNode -> JobTracker

secondary NameNode

DataNode -> TaskTracker

hdfs commands

hdfs [SHELL_OPTIONS] COMMAND [GENERIC_OPTIONS] [COMMAND_OPTIONS]

user commands:

$ hdfs classpath

$ hdfs dfs # 参考 hadoop fs命令
...

admin commands:

$ hdfs balancer
...

debug commands:

$ hdfs verify

$ hdfs recoverLease