Virtualization

Virtualization can be viewed as part of an overall trend in enterprise IT that includes autonomic computing, a scenario in which the IT environment will be able to manage itself based on perceived activity, and utility computing, in which computer processing power is seen as a utility that clients can pay for only as needed. The usual goal of virtualization is to centralize administrative tasks while improving scalability and workloads.

 

Types of virtualization

Software

  • Operating system-level virtualization, hosting of multiple virtualized environments within a single OS instance.
  • Application virtualization and Workspace virtualization, the hosting of individual applications in an environment separated from the underlying OS.
  • Server virtualization is the masking of server resources (including the number and identity of individual physical servers, processors, and operating systems) from server users.

Memory

  • Memory virtualization, aggregating RAM resources from networked systems into a single memory pool.
  • Virtual memory, giving an application programs the impression that it has contiguous working memory, isolating it from the underlying physical memory implementation.

Storage

  • Storage virtualization, the process of completely abstracting logical storage from physical storage.

Data

  • Data virtualization, the presentation of data as an abstract layer, independent of underlying database systems, structures and storage.
  • Database virtualization, the decoupling of the database layer, which lies between the storage and application layers within the application stack.

Network

  • Desktop virtualization, the concept of separating a desktop environment from its physical computer (and its associated operating system) and storing it on another machine across a network, such as a center server. Thin clients employ desktop virtualization.
  • Network virtualization, creation of a virtualized network addressing space within or across network subnets.