A virtual computer system is known as a “virtual machine” (VM): a tightly isolated software container with an operating system and application inside. Each self-contained VM is completely independent. Putting multiple VMs on a single computer enables several operating systems and applications to run on just one physical server, or “host”.
A thin layer of software called a hypervisor decouples the virtual machines from the host and dynamically allocates computing resources to each virtual machine as needed.
Properties of Virtual Machines
VMs have the following characteristics, which offer several benefits.
- Run multiple operating systems on one physical machine
- Divide system resources between virtual machines
- Provide fault and security isolation at the hardware level
- Preserve performance with advanced resource controls
- Save the entire state of a virtual machine to files
- Move and copy virtual machines as easily as moving and copying files
- Provision or migrate any virtual machine to any physical server
Using server virtualization, a company can maximize the use of its server resources and reduce the number of servers required. The result is server consolidation, which improves efficiency and cuts costs.