在任意一个standby的NN节点执行
[root@node02 hadoop-2.5.2]# bin/hdfs haadmin -transitionToActive --forcemanual nn1
You have specified the forcemanual flag. This flag is dangerous, as it can induce a split-brain scenario that WILL CORRUPT your HDFS namespace, possibly irrecoverably.
It is recommended not to use this flag, but instead to shut down the cluster and disable automatic failover if you prefer to manually manage your HA state.
You may abort safely by answering 'n' or hitting ^C now.
Are you sure you want to continue? (Y or N) y
23/06/06 01:37:05 WARN ha.HAAdmin: Proceeding with manual HA state management even though
automatic failover is enabled for NameNode at node02/192.168.56.122:8020
23/06/06 01:37:05 WARN ha.HAAdmin: Proceeding with manual HA state management even though
automatic failover is enabled for NameNode at node01/192.168.56.121:8020
[root@node02 hadoop-2.5.2]#
