There is a lot of software available in the market that can help you create virtual environments, also known as virtual machines, on top of your existing operating system. Creation of a virtual machine is useful if you want to try a new setup or application without affecting your existing configuration. Most of the softwares are available for all platforms, such as Windows, macOS, and different Linux distributions. Some of them are paid and some are free. We will be using Oracle VM VirtualBox, as it is a free open source software available under GNU General Public License (GPL) version 2:

1. Download the latest version of the application from http://www.virtualbox.org/, based on your operation system.
2. Double click on the downloaded file to start setup.

3. Click Next and leave the default options selected, as shown in the following screenshot...

After the successful installation of VirtualBox application, let's go ahead and create our first virtual machine and install Ubuntu Linux on it. Later, we will be using this Ubuntu Linux to configure big data applications and modules. Follow the steps given to set up the VM and install Ubuntu:

1. Download the Ubuntu ISO file from https://www.ubuntu.com/download/desktop.
2. Open the VirtualBox application and click on New. Give a Name to your new virtual machine as shown in the following screenshot:

3. Assign memory (RAM). It is recommended to assign 4GB, as shown in the screenshot that follows:

4. The next step is to Create a virtual hard disk now for your VM, as shown in the screenshot that follows:

5. It will ask you to select the type of virtual hard disk you want to create; keep the default option selected...

Hadoop modules are mostly written in Java, so one of the prerequisites is to install Java. Hadoop daemons requires SSH to encrypt the communication between its nodes in an insecure environment. We will now go through a step by step guide for installing and configuring Java and SSH.

Hadoop is compatible with both Oracle Java and OpenJDK, but it is preferable to install Oracle Java. To install it, use the following instructions:

1. Download JDK and JRE from http://www.oracle.com/technetwork/java/javase/downloads/index.html.
2. Copy the downloaded tar.gz file to the location where you want to install Java.
3. Extract and install Java by using the following command. Make sure...

After the successful installation of the prerequisites, it is now time to start the installation and configuration of Hadoop itself. The following are the steps to get started:

1. Download the stable version of Apache Hadoop from http://www-us.apache.org/dist/hadoop/common/. As of now the stable version available for download is hadoop-2.8.1.

2. Extract the downloaded file by using the following command:

$ tar zxvf hadoop-2.8.1.tar.gz

3. It's time to configure some parameters to run Hadoop. Use the following command to edit the hadoop-env.sh configuration file:

$ gedit etc/hadoop/hadoop-env.sh

4. Look for the following line to set the JAVA_HOME path. Replace /home/hadoopadmin/jdk1.8.0_144/ with the directory where you have installed it. In our case, it will remain the same:

# set to the root of your Java installation
export JAVA_HOME...

In this chapter, we have gone through a step by step guide for installing and setting up a new virtual machine. Then, while using our new virtual machine, we have gone through the installation of Ubuntu to treat it as a dedicated server. We then learnt how to install and configure Apache Hadoop in a single node environment as well as in pseudo-distributed mode. In between, we have also gone through a step by step guide to the installation of the Hadoop prerequisite applications Java and SSH. Now, we are ready to go deeper into the big data world, and will be able to execute our programs.

In the next chapter, we will take a deep dive into the Hadoop echo system, considering the past and present of Hadoop, HDFS, MapReduce, and YARN in detail.