[root@nn01 bin]# ./hadoop namenode -format

12/05/21 06:13:51 INFO namenode.NameNode: STARTUP_MSG:

/************************************************************

STARTUP_MSG: Starting NameNode

STARTUP_MSG:   host = nn01/127.0.0.1

STARTUP_MSG:   args = [-format]

STARTUP_MSG:   version = 0.20.2

STARTUP_MSG:   build = -r 911707; compiled by 'chrisdo' on Fri Feb 19 08:07:34 UTC 2010

************************************************************/

Re-format filesystem in /tmp/hadoop-root/dfs/name ? (Y or N) Y

12/05/21 06:14:01 INFO namenode.FSNamesystem: fsOwner=root,root,bin,daemon,sys,adm,disk,wheel

12/05/21 06:14:01 INFO namenode.FSNamesystem: supergroup=supergroup

12/05/21 06:14:01 INFO namenode.FSNamesystem: isPermissionEnabled=true

12/05/21 06:14:01 INFO common.Storage: Cannot lock storage /tmp/hadoop-root/dfs/name. The directory is already locked.

12/05/21 06:14:01 ERROR namenode.NameNode: java.io.IOException: Cannot lock storage /tmp/hadoop-root/dfs/name. The directory is already locked.

        at org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.lock(Storage.java:510)

        at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1087)

        at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1110)

        at org.apache.hadoop.hdfs.server.namenode.NameNode.format(NameNode.java:856)

        at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:948)

        at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:965)

12/05/21 06:14:01 INFO namenode.NameNode: SHUTDOWN_MSG:

/************************************************************

SHUTDOWN_MSG: Shutting down NameNode at nn01/127.0.0.1

 

./hadoop namenode -format 命令是格式化命名空间。一定是在未启动  hadoop 服务的时候才干执行。出现这个错误提示是由于 hadoop 的服务是子执行状态。