9. Upgrading HDFS Metadata

Run the NameNode upgrade:

runas /user:hadoop "cmd /K hadoop namenode -upgrade"

On each DateNode, start the datanode service:

sc start datanode

Leave the command prompt open until the process completes. To see the status of the upgrade open a browser and connect to the NameNode on port 500070 (http://namenode-host:50070).

	Note
	The amount of time it takes to upgrade HDFS depends upon the amount of data and number of nodes in your environment. It may take only take a few minutes, but could also take an hour.

In the NameNode Administrative Interface verify that the number of DataNodes matches the number of DataNodes in your environment.

Abort the command prompt using ctl+c to end the NameNode upgrade process.

Start the NameNode service:

sc start namenode

Open a browser and connect to the NameNode on port 50070 (http://namenode-host:50070) and verify that SafeMode is off.