Virtualization

In computing, virtualization is a broad term that refers to the abstraction of computer resources:

• Platform virtualization, which separates an operating system from the underlying platform resources
  • Full virtualization
  • Hardware-assisted virtualization
  • Partial virtualization
  • Paravirtualization
  • Operating system-level virtualization
  • Hosted environment (e.g. User-mode Linux)

• Resource virtualization, the virtualisation of specific system resources, such as storage volumes, name spaces, and network resources
  • Encapsulation, the hiding of resource complexity by the creation of a simplified interface
  • Virtual memory, which allows uniform, contiguous addressing of physically separate and non-contiguous memory and disk areas
  • Storage virtualization, the process of completely abstracting logical storage from physical storage
    • RAID - redundant array of independent disks
    • Disk partitioning, is the splitting of a single resource (usually large), such as disk space or network bandwidth, into a number of smaller, more easily utilized resources of the same type
    • Logical volume management, which combines many disks into one large pool and then divides it into logical disks.
  • Network virtualization, creation of a virtualised network addressing space within or across network subnets
  • Channel bonding, the use multiple links combined to work as though they offered a single, higher-bandwidth link
  • I/O virtualization e.g. vNICs, vHBAsz
  • Memory virtualization Aggregates RAM resources from networked systems into virtualised memory pool
• Computer clusters and grid computing, the combination of multiple discrete computers into larger metacomputers

• Application virtualization, the hosting of individual applications on alien hardware/software
  • Portable application
  • Cross-platform virtualization
  • Emulation or simulation
  • Hosted Virtual Desktop
• Virtualization Development, further work in this area

• Desktop virtualization, the remote manipulation of a computer desktop

Virtualization can also refer to:

• a fictional use of this term, in Scanners (Code Lyoko)
• different types of human body and mind virtualisation: Human Virtualisation

Physicalization is the converse approach to virtualised data centers, where, instead of allocating workloads across subdivided, single machine, virtualised resources, the hardware is organized as replicated sets of simple atomic compute resources that are not virtualised. External control software dispatches workloads to these individual atomic compute nodes in much the same way as a VMM manages workload placement in a virtualised system.