What’s the difference between Type 1 (bare metal) and Type 2 (hosted/embedded) Hypervisors?

A hypervisor, also known as a virtual machine monitor (VMM), creates and manages virtual machines (VMs), an important technology in modern computer architecture. A hypervisor enables the virtualization of computers and servers.

Virtualization is a method used to generate virtual representations of physical components, such as server or network resources. The software representation utilizes the fundamental physical resource to function as though it were a physical component. A virtual machine (VM) is a software-based representation of a computer, including components such as memory, processing capability, storage, and an operating system.

Virtual machines are advantageous compared to physical computers because to their mobility, scalability, cost-effectiveness, resource optimization, and reconfiguration. A virtual machine needs a hypervisor for operation.

Type 1 and Type 2 Hypervisor

Type 1 and Type 2 hypervisors are software used to run one or several virtual machines (VMs) on a single physical host. It is a isolated computing environment that consumers view as entirely autonomous from the underlying hardware. The hypervisor is the technology that enables this capability. It administers and distributes physical resources to virtual machines while interfacing with the underlying hardware in the background.

The type 1 hypervisor operates directly on the bare metal server, granting it immediate access to hardware resources. The type 1 hypervisor is frequently referred to as a bare metal hypervisor. The type 2 hypervisor is an application that operates within the host operating system. It is sometimes referred to as a hosted or embedded hypervisor.

Type 1 hypervisor

A type 1 hypervisor, or a bare metal hypervisor, interacts directly with the underlying machine hardware. A bare metal hypervisor is installed directly on the host machine’s physical hardware, not through an operating system. In some cases, a type 1 hypervisor is embedded in the machine’s firmware. The type 1 hypervisor negotiates directly with server hardware to allocate dedicated resources to VMs. It can also flexibly share resources, depending on various VM requests.

Type 2 hypervisor

A type 2 hypervisor, or hosted hypervisor, interacts with the underlying host machine hardware through the host machine’s operating system. You install it on the machine, where it runs as an application. The type 2 hypervisor negotiates with the operating system to obtain underlying system resources. However, the host operating system prioritizes its own functions and applications over the virtual workloads.

Key differences: type 1 vs. type 2 hypervisors

While type 1 and type 2 hypervisors share the common goal to run and coordinate virtual machines (VMs), they have some significant variations.

Resource allocation

Type 1 hypervisors directly access underlying machine resources. They can implement their own custom resource allocation strategies to service their VMs. Type 2 hypervisors negotiate resource allocation with the operating system, which makes the process slower and less efficient.

Ease of management

Managing a type 1 hypervisor and its VM configuration requires system administrator-level knowledge, as it’s relatively complex. In contrast, you can install and manage type 2 hypervisors as an application on an operating system. Even nontechnical users can operate them.

Performance

Type 1 hypervisors offer greater performance to their VMs. This is because they don’t need to negotiate resources with the operating system or travel through the operating system layer. The type 1 hypervisor offers dedicated underlying resources without any negotiation required. Type 2 hypervisors must only use the resources that the operating system is willing to provide.

Isolation

Type 1 hypervisors offer a greater degree of isolation for each virtual environment. There’s no shared layer like there is with the operating system for a type 2 hypervisor. This makes virtual machines running on the type 1 hypervisor inherently more secure. However, updating and patching your virtual machine operating systems is a critical security activity.

When to use: type 1 vs. type 2 hypervisors

Type 1 hypervisors are typically used in data centers, enterprise computing workload situations, web servers, and other primarily fixed-use applications. Cloud computing environments run bare metal hypervisors to offer the most performant virtual machines (VMs) for the underlying physical hardware. Cloud providers also abstract away type 1 hypervisor management and offer VMs as cloud instances you can access through APIs.

Type 2 hypervisors are most often used in desktop and development environments, where workloads are not as resource-intensive or critical to operations. They’re also preferred in cases where users want to simultaneously use two or more operating systems but only have access to one machine.

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