Virtualization
Last updated
Last updated
Virtualization allows us to break the one-to-one relationship of hardware to OS, allowing multiple OS's to run on a single physical server.
Each instance is called a VM (Virtual Machine).
A hypervisor is used to manage and allocate the hardware resources (CPU, RAM, etc) to each VM.
Another name for a hypervisor is VMM (Virtual Machine Monitor).
The type of hypervisor which runs directly on the top of the hardware is called a Type 1 hypervisor.
Examples include VMware ESXi, Microsoft Hyper-V, etc.
Type 1 hypervisors are also called bare-metal hypervisors because they run directly on the hardware (metal).
Another term is native hypervisor.
This is the type of hypervisor used in data center environments.
Type 2 hypervisors run as a program on an operating system like a regular computer program.
Examples include VMware Workstation, Oracle VirtualBox, etc.
The OS running directly on the hardware is called the Host OS, and the OS running in a VM is called a Guest OS.
Another name for a Type 2 hypervisor is hosted hypervisor.
Although Type 2 hypervisors are rarely used in data center environments, they are common on personal-use devices (for example, if a Mac/Linux used needs to run an app that is only supported on Windows, or vice versa).
