In the previous session, you learnt how to launch an EMR and EC2 instance and how to log in to the instance. the use of EC2 -m4. xlarge instance (used in our EMR instances as well ) of AWS cost around INR 19 or $ 0.252 per hour.
In order to manage this cost, development and initial testing of an application can be done in a local system. you can install a virtual machine on your system to do this.
Note:
According to Wikipedia, in the computing context, virtualisation refers to the act of creating a virtual of something including computer hardware platforms , storage devices, computer network resources ,etc. a virtual machine act as a real machine with an operating system. the virtual machines running on the virtualisation layer are also called guest machines.Also, the hardware on which the virtualisation layer runs multiple operating system-is called a host machine the image below shows the difference between traditional and virtual architecture:
The virtualisation layer could be a piece of computer software, firmware or hardware that creates and runs virtual machines. It can run one or more virtual machines on the host system.
The virtualisation layer has software called hypervisor, which is used to share the hardware resources.
Hypervisor
A hypervisor is a software framework that is used to create a virtual machine on the host hardware. It is also known as the virtual machine monitor. It isolates the guest operating system and the applications running on it from the underlying hardware.
Hypervisors are of the following two types:
- Bare Metal/Native Hypervisor: This hypervisor runs directly on the hardware of the host system and has full control over the hardware. A few examples of bare metal hypervisors are Vmware ESX, Microsoft Hyper-V, Xen etc.
- Hosted Hypervisor: The host operating system is the intermediary between the hypervisor and the hardware. The hypervisor satisfies the needs of the guest operating system by interacting with the host operating system. Examples of hosted hypervisor include VirtualBox, Vmware Workstation etc.
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