4. Collect Information

To deploy your Hadoop installation, you need to collect the following information:

The fully qualified domain name (FQDN) for each host in your system, and which component(s) you wish to set up on which host. The Ambari install wizard does not support using IP addresses. You can use hostname -f to check for the FQDN if you do not know it.
The base directories you wish to use as mount points for storing:
- NameNode data
- DataNodes data
- MapReduce data
- ZooKeeper data, if you install ZooKeeper
- Various log, pid, and db files, depending on your install type
The hostname (for an existing instance), database name, username, and password for the MySQL instance, if you install Hive/HCatalog.

	Note
	If you are using an existing instance, the user you create for Hadoop’s use must be granted all privileges.