Hadoop报错“could only be replicated to 0 nodes, instead of 1” .

好长到一段错误代码，呵呵。刚碰到这个问题到时候上网搜了以下，也没有一个很标准的解决方法。大致上说是由于不一致状态导致的。

办法倒是有一个，只不过会丢失掉已有数据，请慎重使用。

1、先把服务都停掉

2、格式化namenode

3、重新启动所有服务

4、可以进行正常操作了

下面是我到解决步骤

root@scutshuxue-desktop:/home/root/hadoop-0.19.2# bin/stop-all.sh
stopping jobtracker
localhost: stopping tasktracker
no namenode to stop
localhost: no datanode to stop
localhost: stopping secondarynamenode
root@scutshuxue-desktop:/home/root/hadoop-0.19.2# bin/hadoop namenode -format
10/07/18 12:46:23 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = scutshuxue-desktop/127.0.1.1
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 0.19.2
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.19 -r 789657; compiled by 'root' on Tue Jun 30 12:40:50 EDT 2009
************************************************************/
Re-format filesystem in /tmp/hadoop-root/dfs/name ? (Y or N) Y
10/07/18 12:46:24 INFO namenode.FSNamesystem: fsOwner=root,root
10/07/18 12:46:24 INFO namenode.FSNamesystem: supergroup=supergroup
10/07/18 12:46:24 INFO namenode.FSNamesystem: isPermissionEnabled=true
10/07/18 12:46:25 INFO common.Storage: Image file of size 94 saved in 0 seconds.
10/07/18 12:46:25 INFO common.Storage: Storage directory /tmp/hadoop-root/dfs/name has been successfully formatted.
10/07/18 12:46:25 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at scutshuxue-desktop/127.0.1.1
************************************************************/
root@scutshuxue-desktop:/home/root/hadoop-0.19.2# ls
bin docs lib README.txt
build.xml hadoop-0.19.2-ant.jar libhdfs src
c++ hadoop-0.19.2-core.jar librecordio test-txt
CHANGES.txt hadoop-0.19.2-examples.jar LICENSE.txt webapps
conf hadoop-0.19.2-test.jar logs
contrib hadoop-0.19.2-tools.jar NOTICE.txt
root@scutshuxue-desktop:/home/root/hadoop-0.19.2# bin/start-all.sh
starting namenode, logging to /home/root/hadoop-0.19.2/bin/../logs/hadoop-root-namenode-scutshuxue-desktop.out
localhost: starting datanode, logging to /home/root/hadoop-0.19.2/bin/../logs/hadoop-root-datanode-scutshuxue-desktop.out
localhost: starting secondarynamenode, logging to /home/root/hadoop-0.19.2/bin/../logs/hadoop-root-secondarynamenode-scutshuxue-desktop.out
starting jobtracker, logging to /home/root/hadoop-0.19.2/bin/../logs/hadoop-root-jobtracker-scutshuxue-desktop.out
localhost: starting tasktracker, logging to /home/root/hadoop-0.19.2/bin/../logs/hadoop-root-tasktracker-scutshuxue-desktop.out
root@scutshuxue-desktop:/home/root/hadoop-0.19.2# bin/hadoop fs -put conf input
root@scutshuxue-desktop:/home/root/hadoop-0.19.2# bin/hadoop dfs -ls
Found 1 items
drwxr-xr-x - root supergroup 0 2010-07-18 12:47 /user/root/input