Hypervisors are an important component of modern IT infrastructure. This article defines a hypervisor, its key benefits, hypervisor advantages and disadvantages, what is hypervisor in virtualization, and how it helps enable edge computing, improve security, and enhance data protection.
Definition: A hypervisor, or virtual machine monitor (VMM), is software that manages virtual machines (VMs) and translates requests between physical and virtual resources. Hypervisors allow a single piece of hardware, called a host, to support multiple VMs, called guests, by virtually sharing its resources like memory, storage, and processing. The hypervisor doesn’t perform the actual CPU execution; it simply manages the resourcing and scheduling.
Hypervisor Examples: you can see a demo of our KVM hypervisor in action here: https://youtu.be/vBcWK3KmTdA
What is a Virtual Machine?
A virtual machine is an emulation of a computer system and provides the functionality of a physical computer. The first virtual machines were created in the 1960s and were based on the principle of time-sharing, which allowed multiple users to use a computer concurrently. While each program seemed to have full access to the machine, only one program was executed at the time, with the system switching between programs in time slices.
Key Benefits of a Hypervisor
Leveraging a hypervisor to host multiple virtual machines is beneficial for several important reasons:
- Easily provision resources for dynamic workloads
- Enables the ability to create virtual machines instantly
- Improves efficiency by only needing one physical server instead of multiple
- Allows you to be hardware-agnostic since the hypervisor separates the operating system from the underlying hardware
- Increases flexibility by allowing your virtual machines to be portable and allows the IT team to shift workloads across multiple servers
- Increases security since virtual machines are isolated from each other
- Allows you to run multiple operating systems on the same hardware
How Hypervisors Enable Edge Computing
Many organizations require computing outside of the main data center to support local systems like POS, ERP, inventory management, and file and print services. However, these satellite locations often don’t have the space or human resources to maintain data centers. That’s why we introduced the HE100 which allows you to seamlessly deploy and maintain smaller, but powerful, nodes to run your virtual machines.
Our hypervisor software within Scale Computing Hypercore allows IT managers to easily and efficiently deploy their workloads on highly available infrastructure outside the data center. Even if connection is lost to the main data center, the local hypervisor will continue to run virtual machines on your nodes so long as it has power. With a hypervisor, IT managers can significantly minimize downtime, quickly provision applications and resources, and simplify their entire data center management.
How Hypervisors Improve Security in your Data Center
One of the primary benefits of using a hypervisor is that it provides an isolated environment for VMs to run. Despite VMs sharing resources, if one VM is attacked, it won’t interfere with anything else running on the same node or cluster. Unless the hypervisor itself is attacked, your VMs will run independently and thus making it more difficult for attackers to bring down multiple systems.
How Hypervisors Enhance Data Protection
On Scale Computing Platform, if a node runs VMs and fails, those virtual disks and data are still available on the remaining cluster nodes. Our system will automatically restart VMs on the remaining nodes. Additionally, you can take multiple point-in-time snapshots of VM storage devices for backup purposes, which all happens nearly instantly and with little impact on production workloads.
Type 1 and Type 2 Hypervisor: Hypervisor Types
There are two types of hypervisors: type 1 and type 2. The main differences between them are as follows:
Type 1 hypervisor:
A type 1 hypervisor is a bare-metal hypervisor that runs directly on the host's hardware. It does not require an underlying operating system to run, as it provides direct access to the physical resources of the host machine to the VMs. Type 1 hypervisors are also called "native" or "bare-metal" hypervisors, and examples include VMware ESXi, Microsoft Hyper-V, and Citrix XenServer.
Type 2 hypervisor:
A type 2 hypervisor runs on top of a host operating system, such as Windows or Linux. It provides an abstraction layer between the physical hardware and the VMs. Type 2 hypervisors are also called "hosted" hypervisors, and examples include Oracle VirtualBox, VMware Workstation, and Parallels Desktop.
Is KVM a Type 1 Hypervisor?
Yes, KVM (Kernel-based Virtual Machine) is a type 1 hypervisor. It is a virtualization infrastructure for the Linux kernel that turns it into a hypervisor, allowing multiple virtual machines (VMs) to share the same hardware resources of a physical machine. KVM runs directly on the host machine's hardware and provides virtualization services to guest operating systems, making it a type 1, or bare-metal hypervisor.
In summary, type 1 hypervisors run directly on the host hardware, while type 2 hypervisors run on top of a host operating system. Type 1 hypervisors are typically used in data centers and other enterprise environments, where performance and security are critical, while type 2 hypervisors are often used for desktop virtualization and development/testing environments.