The HDFS Service
The HDFS service, and specifically the NameNode, has a number of configuration options that are unique to it. This includes configuring HDFS for high availability, including the ability to automatically or manually fail over to a backup NameNode, and setting up multiple federated nameservices. This section also include information on how to move the NameNode from one host to another, and how to run the Balancer.
Formatting the NameNode and Creating the /tmp Directory
When adding the HDFS service, the Add Host wizard automatically formats the NameNode and creates the /tmp directory on HDFS. If you quit the Add Host wizard or it does not finish, you can format the NameNode and create the /tmp directory outside the wizard by doing these steps:
- Stop the HDFS service if it is running. See Starting, Stopping, and Restarting Services.
- In the HDFS > Status tab, choose Format from the Actions menu.
- In the HDFS > Status tab, choose Create /tmp Directory from the Actions menu.
- Start the HDFS service. See Starting, Stopping, and Restarting Services.