Virtualization technology - the basis of cloud computing

Virtualization refers to running multiple virtual computers, or virtual machines, inside a single physical computer. While the basic idea of virtualization is old (dating back to mainframe computers in 1960s), it has become mainstream only in the last 10-15 years. Today, most new servers are virtualized.

  • Hypervisor is the operating system running on actual hardware. Virtual machines run as processes within this operating system. Sometimes the hypervisor is called Dom0 or Domain 0.

  • Virtual machine is a virtual computer running under a hypervisor.

  • Container is a lightweight virtual machine that runs under the same operating system instance (kernel) as the hypervisor. Essentially, a container is nothing but a group of processes with their own name space for process identifiers etc.

  • Virtual network is a logical network within a server, or possibly extending to multiple servers or even multiple data centers.

  • Virtualization software is software that implements virtualization on a computer. It can be part of an operating system (or a special version of an operating system) or an application software package.

Virtualization is the basis of modern cloud computing.

Contents

Why Virtualize?

Why Virtualize?

Virtualization drivers in recent years have included:

  • More powerful hardware, allowing each machine to run multiple applications simultaneously

  • Pressure to lower IT costs and simplify IT administration

  • Need to manage large-scale installations and clusters, such as server farms

  • Improved security, reliability, scalability, and device independence

  • Ability to mix multiple operating systems on same hardware.