Hypervisor – Definition & Detailed Explanation – Virtual Computer Glossary Terms

I. What is a Hypervisor?

A hypervisor, also known as a virtual machine monitor (VMM), is a software or firmware that creates and runs virtual machines (VMs). These VMs are isolated instances of operating systems that run on a single physical machine. The hypervisor allows multiple VMs to run simultaneously on the same hardware, enabling efficient use of resources and improved flexibility in managing IT infrastructure.

II. Types of Hypervisors

There are two main types of hypervisors: Type 1 and Type 2.

Type 1 hypervisors, also known as bare-metal hypervisors, run directly on the host’s hardware to control the hardware and to manage guest operating systems. Examples of Type 1 hypervisors include VMware ESXi, Microsoft Hyper-V, and Citrix XenServer.

Type 2 hypervisors, also known as hosted hypervisors, run on a conventional operating system just like other computer programs. They are typically used for testing and development purposes. Examples of Type 2 hypervisors include VMware Workstation, Oracle VirtualBox, and Parallels Desktop.

III. Benefits of Using a Hypervisor

Using a hypervisor offers several benefits, including:

1. Server Consolidation: Hypervisors allow multiple VMs to run on a single physical server, reducing the number of physical servers needed in a data center.

2. Resource Optimization: Hypervisors allocate resources dynamically to VMs based on their workload, improving resource utilization and performance.

3. Disaster Recovery: Hypervisors enable easy backup and restoration of VMs, making disaster recovery processes more efficient.

4. Cost Savings: By reducing the number of physical servers needed and optimizing resource usage, hypervisors can lead to cost savings in terms of hardware, power, and cooling.

IV. How Does a Hypervisor Work?

A hypervisor works by abstracting the physical hardware of a computer and creating virtual machines that mimic the behavior of physical machines. The hypervisor manages the allocation of resources, such as CPU, memory, storage, and network, to each VM. It also isolates VMs from each other to ensure security and stability.

When a VM is created, the hypervisor allocates a portion of the physical hardware resources to it, creating a virtual environment in which the guest operating system can run. The hypervisor intercepts and translates hardware requests from the VM to the physical hardware, ensuring that each VM operates independently and securely.

V. Common Features of Hypervisors

Some common features of hypervisors include:

1. Live Migration: The ability to move a running VM from one physical server to another without downtime.

2. Snapshot: The ability to capture the state of a VM at a specific point in time for backup or testing purposes.

3. High Availability: The ability to automatically restart VMs on another physical server in case of hardware failure.

4. Resource Pooling: The ability to allocate and manage resources across multiple VMs based on their workload.

VI. Considerations When Choosing a Hypervisor

When choosing a hypervisor, consider the following factors:

1. Type of Workload: Different hypervisors are optimized for different workloads, so choose one that best fits your specific use case.

2. Compatibility: Ensure that the hypervisor is compatible with your existing hardware and software environment.

3. Management Tools: Consider the ease of use and availability of management tools for the hypervisor.

4. Licensing Costs: Evaluate the licensing costs associated with the hypervisor and compare them with your budget.

In conclusion, hypervisors play a crucial role in modern IT infrastructure by enabling efficient resource utilization, flexibility, and cost savings. Understanding the types, benefits, working principles, features, and considerations of hypervisors can help organizations make informed decisions when implementing virtualization solutions.