24. An Overview of Virtualization Techniques
Virtualization is generically defined as the ability to run multiple operating systems simultaneously on a single computer system. While not necessarily a new concept, Virtualization has come to prominence in recent years because it provides a way to fully utilize the CPU and resource capacity of a server system while providing stability (in that if one virtualized guest system crashes, the host and any other guest systems continue to run).
Virtualization is also useful in terms of trying out different operating systems without having to configure dual boot environments. For example, you can run Windows in a virtual machine without having to re-partition the disk, shut down Ubuntu and then boot from Windows. You simply start up a virtualized version of Windows as a guest operating system. Similarly, virtualization allows you to run other Linux distributions from within an Ubuntu system, providing concurrent access to both operating systems...
