Virtualization forms a solid foundation for all cloud architectures. It enables the abstraction and aggregation of all data center resources, thereby creating a unified resource that can be shared by all application loads. Hardware such as servers, storage devices, and other components are treated as a pool of resources rather than a discrete system, thereby allowing the allocation of resources on demand. By decoupling the physical IT infrastructure from the applications and services being hosted, virtualization allows greater efficiency and flexibility, without any effect on system administration productivity or tools and processes . By separating the workload from the underlying OS and hardware, virtualization allows extreme portability.
Figure shows an example of vitrualisation: in non cloud computing there is a need for three servers; in cloud computing two servers are used.
Vitrual Workspaces:
- An abstraction of an executing environment that can be made dynamically available to authorised to clients by using well defined protocols
- Resource quota(e.g. CPU, memory share)
- Software configuration(e.g O/S, provided services)
- Implement on Virtual Machines:
- Abstraction of a physical host machine
- Hypervisor intercepts and emulates instructions from VMs, and allow management of VMs
VM technology allows multiple virtual machines to run on a single physical machine.
