Virtual Machine

Virtual Machines

With multiple-core processors and tons of memory available, it is common practice today to set up servers as virtual machines. A virtual machine (VM) is the process of running a separate computer in software on top of one set of hardware. Generally, the process is used to run multiple virtual computers on a single set of hardware. Basically, one physical set of hardware is configured to run multiple operating systems at the same time so it appears to be several separate computers.

One physical computer is used to host three separate computers. The hosted VMs are often servers, but the technique can also be used for personal computers. The goal is to allocate hardware resources to the VMs that need the additional computing power. The technique can save money, space, and electrical power, by reducing the amount

of physical hardware. It is also useful for separating tasks. Some server software can interfere with other tools and it is often easier to run them separately. VMs also make it significantly easier to backup and restore the entire computer.

Once the VM is created, it is stored as a software file on the drives. If anything goes wrong, the file can be reloaded and the entire VM is recreated immediately— without needing to reinstall the operating system and all of the applications. On personal computers, the VM technique can be used for creating development and test environments. One system could be used for day-to-day work, and another for testing experimental software. If the experimental software causes problems, the entire VM can be deleted with no effects on the production computer.