Hypervisor definition
A hypervisor, or virtual machine monitor (VMM), is software, firmware, or hardware that creates and manages virtual machines (VMs). Hypervisors provide the means for a host computer to support multiple guest VMs, each with its operating system (OS) and applications running simultaneously and independently.
See also: Intel virtualization technology, data center virtualization, host virtual machine
Hypervisor examples
- Server virtualization: Businesses use hypervisors to create a virtualized environment, allowing multiple VMs to run on a single server to maximize resource utilization.
- Testing environments: Developers use hypervisors to create isolated VMs for testing applications on different operating systems without needing separate hardware for each.
Hypervisor types and comparison
Two main types of hypervisors exist: Type 1, also called “bare metal,” and Type 2, or “hosted.”
Type 1 hypervisors run directly on the system's hardware to control and manage the guest VMs, offering high performance and efficiency. Examples include Microsoft Hyper-V and VMware ESXi.
Type 2 hypervisors run as an application on an existing host OS, providing a less efficient but more user-friendly option for consumer use. Examples include Oracle VirtualBox and VMware Workstation.
Advantages and disadvantages of hypervisors
Pros:
- Efficiency: Hypervisors enable better utilization of system resources by distributing them among multiple VMs.
- Isolation: Each VM operates independently, enhancing security and stability.
Cons:
- Resource demand: Running multiple VMs requires a significant amount of system resources, which may slow down system performance.
- Complex management: Managing multiple VMs and their respective operating systems can be complicated.
Using hypervisors
- Ensure your system has enough resources (CPU, memory, and storage) to handle the number of VMs you plan to run.
- Choose the right type of hypervisor based on your needs, considering factors like performance, ease of use, and cost.