Introducing virtualization
In the domain of computer architecture, virtualization refers to the use of hardware and software to create an emulated version of an environment in which a piece of software runs, as opposed to the real environment in which the code normally expects to run.
We have already looked at one form of virtualization in Chapter 7, Processor and Memory Architectures, in some depth: virtual memory. Virtual memory uses software, with supporting hardware, to create an environment in which each running application functions as if it has exclusive access to the entire computer, including all the memory it requires at the addresses it expects. This allows the virtual address ranges used by a program to be the same as those in use by other currently running processes.
Systems using virtual memory create multiple sandboxed environments in which each application runs without interference from other applications, except in competition for shared system resources.
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