(1) In practice, the term may refer to the more traditional virtualization method rather than the technique described below (see virtual machine).|
(2) A method for splitting a single computer into multiple partitions called "virtual environments" (VEs), in order to prevent applications from interfering with each other. A virtual environment (VE) is also called a "virtual private server" (VPS) or "container."
The OS virtualization method differs from the traditional "virtual machine" (VM) method, because it supports only the same operating system in each partition rather than different operating systems running simultaneously. Also called "operating system-level virtualization," OS virtualization replicates components of the host operating system into each virtual environment (VE). Therefore, if the operating system were Linux, all VEs must run Linux. For several usage scenarios that explain the benefits of virtualization, see virtual machine.
Advantages Over Virtual Machines (VMs)
In the traditional virtual machine method, each of the operating systems communicates through an abstraction layer to the hardware. The more VMs running at the same time, the more the entire system slows. However, virtual environments (VEs) communicate directly to the host operating system as in a non-virtualized computer, and performance is improved.
Because OS virtualization partitions can be much smaller than virtual machine partitions, many more can run in the same hardware configuration. In fact, hundreds of virtual environments (VEs) can exist in a single machine. An example of OS virtualization software is SWsoft's Virtuozzo (see Virtuozzo). Contrast with virtual machine.