Readying your system

Before you start with the prerequisites, you must ensure that you have sufficient space on your Hadoop nodes, and that you are using the respective directory appropriately. First, find out how much available disk space you have with the following command, also shown in the screenshot:

hrishikesh@base0:/$ df -m

The preceding command should present you with insight about the space available in MBs. Note that Apache Hadoop can be set up on a root user account or separately; it is safe to install it on a separate user account with space.

Although you need root access to these systems and Hadoop nodes, it is highly recommended that you create a user for Hadoop so that any installation impact is localized and controlled. You can create a user with a home directory with the following command:

hrishikesh@base0:/$ sudo adduser hadoop

The preceding command will prompt you for a password and will create a home directory for a given user in the default location (which is usually /home/hadoop). Remember the password. Now, switch the user to Hadoop for all future work using the following command:

hrishikesh@base0:/$ su - hadoop

This command will log you in as a Hadoop user. You can even add a Hadoop user in the sudoers list, as given here.