报错：
replicated to 0 nodes instead of minReplication (=1). There are 1 datanode(s) running and 1 node(s) are excluded in this operation.
解决方案：
这是因为有一个datanode掉线了
方案1：重启机器，重新开启hadoop集群发现掉线的那个节点的日志报错：
WARN org.apache.hadoop.hdfs.server.datanode.DataNode: DatanodeRegistration(10.1.9.130, datanodeUuid=c2e3a84b-7ee9-4639-b71f-9ad52b035607, infoPort=50075, ipcPort=50020, storageInfo=lv=-56;cid=CID-c5d0c1e2-df6c-41e0-b2fd-8773d8be24eb;nsid=1484736644;c=0):Failed to transfer BP-518714262-10.1.9.203-1449666013934:blk_1073741862_1038 to 10.1.9.204:50010 got
java.net.NoRouteToHostException: No route to host
确认是宁外一个节点的防火墙没有关闭导致的
关闭防火墙即可
service iptables stop
chkcongfig iptables off