In computing, virtualization is a broad term that refers to the abstraction of computer resources. One useful definition is "a technique for hiding the physical characteristics of computing resources from the way in which other systems, applications, or end users interact with those resources. This includes making a single physical resource (such as a server, an operating system, an application, or storage device) appear to function as multiple logical resources; or it can include making multiple physical resources (such as storage devices or servers) appear as a single logical resource."^[1] Memory (Random Access Memory) Look up computing in Wiktionary, the free dictionary. ... abstraction in general. ... Application has the following meanings: In general, an application is using something abstract for a more concrete use. ... Economics and commerce define an end-user as the person who uses a product. ... Look up server in Wiktionary, the free dictionary. ... An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. ... A storage device is a device used for storing something. ...

However, the term is an old one: It has been widely used since the 1960s or earlier, and has been applied to many different aspects and scopes of computing — from entire computer systems to individual capabilities or components. The common theme of all virtualization technologies is the hiding of technical detail, through encapsulation. Virtualization creates an external interface that hides an underlying implementation, e.g. by multiplexing access, by combining resources at different physical locations, or by simplifying a control system. Recent development of new virtualization platforms and technologies has refocused attention on this mature concept. The 1960s decade refers to the years from January 1, 1960 to December 31, 1969, inclusive. ... Encapsulation may refer to: information hiding and separation of concerns, in software engineering, the process of enclosing programming elements inside larger, more abstract entities integrated circuit encapsulation, in electronics the design and manufacture of protective packages micro-encapsulation, means to confine material molecular encapsulation, means to confine molecules encapsulation (pharmacology... In telecommunications, multiplexing (also muxing or MUXing) is the combining of two or more information channels onto a common transmission medium using hardware called a multiplexer or (MUX). ...

Like such terms as abstraction and object orientation, virtualization is used in many different contexts. This article reviews common uses of the term, divided into two main parts: abstraction in general. ... Object-oriented programming (OOP) is a computer programming paradigm in which a software system is modeled as a set of objects that interact with each other. ...

• Platform virtualization involves the simulation of virtual machines.
• Resource virtualization involves the simulation of combined, fragmented, or simplified resources.

Of course, virtualization is also an important concept in non-computer contexts. Many control systems implement a virtualized interface to a complex device; thus a modern car's gas pedal does much more than just increase the flow of fuel to the engine; and a fly-by-wire system presents a simplified "virtual airplane" which may have little to do with the physical implementation. In general terms, a virtual machine in computer science is software that creates an environment between the computer platform and the end user in which the end user can operate software. ... It has been suggested that this article or section be merged with Control theory. ... A flight control system consists of the flight control surfaces, the respective cockpit controls, connecting linkage, and necessary operating mechanisms to control aircraft in flight The basic fundamentals of aircraft controls has been explained in aeronautics. ...

An also useful concept is that which opposes virtualization to transparency: something is virtual when is visible, perceivable, but does not physically exist in the form perceived (e.g. virtual storage); and is transparent when it exists in the real world, but is not visible in use (e.g. location transparency). In human-computer interaction, computer transparency is an aspect of user friendliness which prevents the user from worrying about technical details (like installation, updating, downloading or device drivers). ...

Platform virtualization

The original sense of the term virtualization, dating from the 1960s, is in the creation of a virtual machine using a combination of hardware and software. For convenience, we will call this platform virtualization. The term virtual machine apparently dates from the IBM M44/44X experimental paging system. The creation and management of virtual machines has also been referred to as creating pseudo machines, in the early CP-40 days, and server virtualization more recently. The terms virtualization and virtual machine have both also acquired additional meanings through the years. In computer science, a virtual machine is software that creates a virtualized environment between the computer platform and its operating system, so that the end user can operate software on an abstract machine. ... The IBM M44/44X was an experimental computer system from the mid 1960s, designed and operated at IBMs Thomas J. Watson Research Center at Yorktown Heights, New York. ... [Note: This and several related articles are still evolving. ...

Platform virtualization is performed on a given hardware platform by "host" software (a control program), which creates a simulated computer environment (a virtual machine) for its "guest" software. The "guest" software, which is often itself a complete operating system, runs just as if it were installed on a stand-alone hardware platform. Typically, many such virtual machines are simulated on a given physical machine. For the "guest" system to function, the simulation must be robust enough to support all the guest system's external interfaces, which (depending on the type of virtualization) may include hardware drivers. An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. ...

There are several approaches to platform virtualization, listed below based on how complete a hardware simulation is implemented. (The following terms are not universally-recognized as such, but the underlying concepts are all found in the literature.)

Emulation or simulation 

the virtual machine simulates the complete hardware, allowing an unmodified "guest" OS for a completely different CPU to be run. This approach has long been used to enable the creation of software for new processors before they were physically available. Examples include Bochs, PearPC, PowerPC version of Virtual PC, QEMU without acceleration, and the Hercules emulator. Emulation is implemented using a variety of techniques, from state machines to the use of dynamic recompilation on a full virtualization platform.

Native virtualization and full virtualization 

the virtual machine simulates enough hardware to allow an unmodified "guest" OS (one designed for the same CPU) to be run in isolation. Typically, many instances can be run at once. This approach was pioneered in 1966 with CP-40 and CP[-67]/CMS, predecessors of IBM's VM family. Examples include VirtualBox, Virtual Iron, Virtual PC, VMware Workstation, VMware Server (formerly GSX Server),VMware ESX Server, QEMU, Parallels Desktop, Adeos, Mac-on-Linux, Win4BSD, Win4Lin Pro, and z/VM.

Partial virtualization (and including "address space virtualization") 

the virtual machine simulates multiple instances of much (but not all) of an underlying hardware environment, particularly address spaces. Such an environment supports resource sharing and process isolation, but does not allow separate "guest" operating system instances. Although not generally viewed as a virtual machine category per se, this was an important approach historically, and was used in such systems as CTSS, the experimental IBM M44/44X, and arguably systems like MVS. (Many more recent systems, such as Microsoft Windows and Linux, as well as the remaining categories below, also use this basic approach.)

Paravirtualization 

the virtual machine does not necessarily simulate hardware, but instead (or in addition) offers a special API that can only be used by modifying the "guest" OS. This system call to the hypervisor is called a "hypercall" in Xen, Parallels Workstation and Enomalism; it is implemented via a DIAG ("diagnose") hardware instruction in IBM's CMS under VM (which was the origin of the term hypervisor). Examples include Win4Lin 9x, Sun's Logical Domains, and z/VM.

Operating system-level virtualization 

virtualizing a physical server at the operating system level, enabling multiple isolated and secure virtualized servers to run on a single physical server. The "guest" OS environments share the same OS as the host system – i.e. the same OS kernel is used to implement the "guest" environments. Applications running in a given "guest" environment view it as a stand-alone system. Examples are Linux-VServer, Virtuozzo (for Windows or Linux), OpenVZ, Solaris Containers, and FreeBSD Jails.

Application Virtualization 

running a desktop or server application locally, using local resources, within an appropriate virtual machine; this is in contrast with running the application as conventional local software, i.e. software that has been 'installed' on the system. (Compare this approach with Software installation and Terminal Services.) Such a virtualized application runs in a small virtual environment containing the components needed to execute – such as registry entries, files, environment variables, user interface elements, and global objects. This virtual environment acts as a layer between the application and the operating system, and eliminates application conflicts and application-OS conflicts. Examples include the Sun Java Virtual Machine, Softricity, Thinstall, Altiris, Portable Apps, and Trigence. (This approach to virtualization is clearly different from the preceding ones; only an arbitrary line separates it from such virtual machine environments as Smalltalk, FORTH, Tcl, P-code, or any interpreted language.)

As of 2006, recent tools and technologies for virtualization are providing new alternatives for application virtualization and application streaming. This article is about emulation in computer science. ... Look up simulation in Wiktionary, the free dictionary. ... Bochs for Windows displaying HAL91 (Linux) Bochs is a portable open source x86 and AMD64 PCs emulator mostly written in C++ and distributed under GNU Lesser General Public License. ... PearPC on Ubuntu PearPC logo PearPC is an architecture-independent PowerPC platform emulator capable of running many PowerPC operating systems, including Mac OS X, Darwin and Linux. ... Virtual PC is a virtualization suite for Apple Mac OS X and Microsoft Windows operating systems, originally created by Connectix, subsequently acquired by Microsoft. ... It has been suggested that Qemu-Launcher be merged into this article or section. ... Hercules logo The Hercules emulator is an emulator for the IBM mainframe hardware: the System/370, System/390 and zSeries computers. ... In the theory of computation, a finite state machine (FSM) or finite state automaton (FSA) is an abstract machine that has only a finite, constant amount of memory. ... In computer science, dynamic recompilation (sometimes abbreviated to dynarec) is a feature of some emulators and virtual machines, where the system may recompile some part of a program during execution. ... Note: The concept of full virtualization is well established in the literature, but not always using this specific term. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... Note: The concept of full virtualization is well established in the literature, but not always using this specific term. ... [Note: This and several related articles are still evolving. ... VM/CMS (Virtual Machine/Conversational Monitor System, originally called CP/CMS when it first appeared) is an IBM system used on System/360, System/370, System/390 and zSeries IBM mainframes. ... VM is an early and influential virtual machine operating system from IBM, apparently the first true virtual machine system. ... VirtualBox by InnoTek is an x86 virtualizer for Windows and Linux 32-bit hosts supporting Windows, Linux 2. ... Virtual Iron Software, located in Lowell, Massachusetts, provides software for virtualization and management of a virtual infrastructure. ... Virtual PC is a virtualization suite for Apple Mac OS X and Microsoft Windows operating systems, originally created by Connectix, subsequently acquired by Microsoft. ... VMware Inc. ... VMware Inc. ... VMware Inc. ... It has been suggested that Qemu-Launcher be merged into this article or section. ... Parallels Workstation is the first commercial software product released by Parallels, Inc. ... Adeos stands for Adaptive Domain Environment for Operating Systems. ... Mac-on-Linux is an open source virtual machine program for running Mac OS on PPC Linux computers. ... Win4Lin is a software application for Linux which allows a user to run a copy of Microsoft Windows 95, 98, Me, 2000 or XP applications on their desktop. ... VM is an early and influential virtual machine operating system from IBM, apparently the first true virtual machine system. ... Note: The concept of partial virtualization is well established in the literature, but not always using this specific term. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... In computer science, a virtual machine is software that creates a virtualized environment between the computer platform and its operating system, so that the end user can operate software on an abstract machine. ... CTSS, which stood for the Compatible Time-Sharing System, was one of the first time-sharing operating systems; it was developed at MITs Computation Center. ... The IBM M44/44X was an experimental computer system from the mid 1960s, designed and operated at IBMs Thomas J. Watson Research Center at Yorktown Heights, New York. ... MVS (Multiple Virtual Storage) was the most commonly used operating system on the System/370 and System/390 IBM mainframe computers. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... It has been suggested that Criticism of Linux be merged into this article or section. ... In computing, paravirtualization is a virtualization technique that presents a software interface to virtual machines that is similar but not identical to that of the underlying hardware. ... A hypervisor in computing is a scheme which allows multiple operating systems to run, unmodified, on a host computer at the same time. ... Xen is a free virtual machine monitor for IA-32, x86-64, IA-64 and PowerPC architectures. ... This article does not cite any references or sources. ... Enomalism is a management console for the Xen Hypervisor. ... The Conversational Monitor System (CMS) is a relatively simple interactive computing single-user operating system which was for many years IBMs principal time-sharing product. ... VM is an early and influential virtual machine operating system from IBM, apparently the first true virtual machine system. ... Win4Lin is a software application for Linux which allows a user to run a copy of Microsoft Windows 95, 98, Me, 2000 or XP applications on their desktop. ... Sun Microsystems Logical Domains (LDoms) technology offers a virtualized computing environment abstracted from all physical devices. ... VM is an early and influential virtual machine operating system from IBM, apparently the first true virtual machine system. ... Operating System Virtualization is a server virtualization technology which virtualizes servers on an operating system (kernel) layer. ... Linux-VServer is a virtual private server implementation done by adding operating system-level virtualization capabilities to the Linux kernel. ... Virtuozzo is a proprietary operating system virtualization product produced by SWsoft, Inc. ... OpenVZ is an operating system-level virtualization technology based on the Linux kernel and operating system. ... Solaris Containers (formerly known as Solaris Zones) is a virtualization feature first available with Solaris 10. ... The FreeBSD jail mechanism allows administrators to partition a FreeBSD-based computer system into several independent mini-systems called jails. ... Application Virtualization is a field within computer science which deals with breaking the age old bond between physical hardware, operating system, and the program which runs on top of them. ... Look up desktop in Wiktionary, the free dictionary. ... This article or section does not cite any references or sources. ... It has been suggested that this article or section be merged into Installer. ... Terminal Services or Terminal Server Edition (TSE) is a component of Microsoft Windows operating systems (both client and server versions) that allows a user to access applications or data stored on a remote computer over a network connection. ... An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. ... A Java Virtual Machine (JVM), originally developed by Sun Microsystems, is a virtual machine that executes Java bytecode. ... Altiris is a worldwide software company that was started in 1998 when it split off of a company called KeyLabs. ... For other uses, see Small Talk (disambiguation). ... Forth is a programming language and programming environment, initially developed by Charles H. Moore at the US National Radio Astronomy Observatory in the early 1970s. ... Tcl (originally from Tool Command Language, but nonetheless conventionally rendered as Tcl rather than TCL; and pronounced tickle) is a scripting language created by John Ousterhout. ... A p-code is similar to a byte-code but a p-code works at a higher level. ... In computer programming, an interpreted language is a programming language whose programs may be executed from source form, by an interpreter. ... 2006 is a common year starting on Sunday of the Gregorian calendar. ... // Timelines 1960 IBM Sun Hewlett-Packard 1999 February 8, 1999, VMware introduced VMware Virtual Platform. ... Application streaming is the new software distribution method using application virtualization. ...

Resource virtualization

The basic concept of platform virtualization, described above, was later extended to the virtualization of specific system resources, such as storage volumes, name spaces, and network resources.

• Resource aggregation, spanning, or concatenation combines individual components into larger resources or resource pools. For example:
  • RAID and volume managers combine many disks into one large logical disk.
  • Storage Virtualization refers to the process of completely abstracting logical storage from physical storage, and is commonly used in SANs. The physical storage resources are aggregated into storage pools, from which the logical storage is created. Multiple independent storage devices, which may be scattered over a network, appear to the user as a single, location-independent, monolithic storage device, which can be managed centrally.
  • Channel bonding and network equipment use multiple links combined to work as though they offered a single, higher-bandwidth link.
  • Virtual Private Network (VPN), Network Address Translation (NAT), and similar networking technologies create a virtualized network namespace within or across network subnets.
  • Multiprocessor and multi-core computer systems often present what appears as a single, fast processor.

• Computer clusters, grid computing, and virtual servers use the above techniques to combine multiple discrete computers into larger metacomputers.

• 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. This is sometimes also called "zoning," especially in storage networks.

• Encapsulation is the hiding of resource complexity by the creation of a simplified interface. For example, CPUs often incorporate cache memory or pipelines to improve performance, but these elements are not reflected in their virtualized external interface. Similar virtualized interfaces hiding complex implementations are found in disk drives, modems, routers, and many other "smart" devices.

Look up Aggregation in Wiktionary, the free dictionary The term aggregation may refer to— in economics, combining entities into a single entity which represent them, like aggregation of individual demand to total, or market, demand. ... Look up spanning in Wiktionary, the free dictionary. ... Concatenation is a standard operation in computer programming languages (a subset of formal language theory). ... In computing, a redundant array of inexpensive disks, also later known as redundant array of independent disks (commonly abbreviated RAID) is a system which uses multiple hard drives to share or replicate data among the drives. ... In computer storage, logical volume management or LVM is a method of allocating space on mass storage devices that is more flexible than conventional partitioning schemes. ... Storage Virtualization refers to the process of completely abstracting logical storage from physical storage. ... In computing, a storage area network (SAN) is an architecture to attach remote computer storage devices such as disk array controllers, tape libraries and CD arrays to servers in such a way that to the operating system the devices appear as locally attached devices. ... Channel bonding in computer networking is an arrangement in which two or more network interfaces on a host computer are combined for redundancy or increased throughput. ... A virtual private network (VPN) is a private communications network often used by companies or organizations, to communicate confidentially over a public network. ... In computer networking, the process of network address translation (NAT, also known as network masquerading, native address translation or IP masquerading) involves re-writing the source and/or destination addresses of IP packets as they pass through a router or firewall. ... Multiprocessing is traditionally known as the use of multiple concurrent processes in a system as opposed to a single process at any one instant. ... A dual-core CPU combines two independent processors and their respective caches and cache controllers onto a single silicon chip, or integrated circuit. ... An example of a Computer cluster A computer cluster is a group of loosely coupled computers that work together closely so that in many respects they can be viewed as though they are a single computer. ... Grid computing is an emerging computing model that provides the ability to perform higher throughput computing by taking advantage of many networked computers to model a virtual computer architecture that is able to distribute process execution across a parallel infrastructure. ... In computer engineering, hard disk drive partitioning is the creation of logical divisions upon a hard disk that allows one to apply operating system-specific logical formatting. ... Encapsulation may refer to: information hiding and separation of concerns, in software engineering, the process of enclosing programming elements inside larger, more abstract entities integrated circuit encapsulation, in electronics the design and manufacture of protective packages micro-encapsulation, means to confine material molecular encapsulation, means to confine molecules encapsulation (pharmacology... CPU can stand for: in computing: Central processing unit in journalism: Commonwealth Press Union in law enforcement: Crime prevention unit in software: Critical patch update, a type of software patch distributed by Oracle Corporation in Macleans College is often known as Ash Lim. ... Look up cache in Wiktionary, the free dictionary. ...

Virtualization examples

The following examples illustrate applications of virtualization.

Server consolidation 

Virtual machines are used to consolidate many physical servers into fewer servers, which in turn host virtual machines. Each physical server is reflected as a virtual machine "guest" residing on a virtual machine host system. This is also known as Physical-to-Virtual or 'P2V' transformation.

Disaster recovery 

Virtual machines can be used as "hot standby" environments for physical production servers. This changes the classical "backup-and-restore" philosophy, by providing backup images that can "boot" into live virtual machines, capable of taking over workload for a production server experiencing an outage.

Testing and training 

Hardware virtualization can give root access to a virtual machine. This can be very useful such as in kernel development and operating system courses.^[2]

Portable applications 

Certain application configuration mechanisms such as the registry on the Microsoft Windows platform lead to well-known issues involving the creation of portable applications. For example, many applications cannot be run from a removable drive without installing them on the system's main disk drive. This is a particular issue with USB drives. Virtualization can be used to encapsulate the application with a redirection layer that stores temporary files, Windows Registry entries, and other state information in the application's installation directory – and not within the system's permanent file system. See portable applications for further details. It is unclear whether such implementations are currently available.

Portable workspaces 

Recent technologies have used virtualization to create portable workspaces on devices like iPods and USB memory sticks. These products include:

• Application Level – Thinstall – which is a driver-less solution for running "Thinstalled" applications directly from removable storage without system changes or needing Admin rights
• OS-level – MojoPac, Ceedo, Aargo and U3 – which allows end users to install some applications onto a storage device for use on another PC.
• Machine-level – moka5 and LivePC – which delivers an operating system with a full software suite, including isolation and security protections.

Hardware virtualization technologies

• Intel Vanderpool x86 virtualization
• AMD Pacifica x86 virtualization
• Sun UltraSPARC T1 hypervisor
• IBM Advanced POWER virtualization

Also known as P2V Physical-to-Virtual describes the process of decoupling and migrating a physical servers OS, applications, and data from a physical server to a virtual machine guest hosted on a virtualization platform. ... A USB drive, shown with a 24 mm US quarter coin for scale. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... A USB drive, shown with a 24 mm US quarter coin for scale. ... A USB drive, shown with a 24 mm US quarter coin for scale. ... Encapsulation may refer to: information hiding and separation of concerns, in software engineering, the process of enclosing programming elements inside larger, more abstract entities integrated circuit encapsulation, in electronics the design and manufacture of protective packages micro-encapsulation, means to confine material molecular encapsulation, means to confine molecules encapsulation (pharmacology... To meet Wikipedias quality standards, this article or section may require cleanup. ... The Registry Editor in Windows Vista By- Laxmikant Sharma, Retina-X, Jaipur, India. ... A USB drive, shown with a 24 mm US quarter coin for scale. ... iPod (fifth generation) in Apple Universal Dock, iPod nano (second generation) and iPod shuffle (second generation) iPod is a brand of portable media players designed and marketed by Apple and launched in 2001. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... MojoPac is a software virtualization product from RingCube Technologies. ... U3 LLC is a joint venture that is backed by Sandisk and its subdsidiary, M-Systems. ... moka5 was founded, in 2005, by a group of PhD types from Stanford and their professor, Dr. Monica Lam. ... LivePCs are virtual PCs that you can create and share. ... Virtualization Technology allows a single machine to run multiple operating systems at once. ... Virtualization Technology is the name of the mutually incompatible virtualization technologies from Intel and AMD, previously known by their respective codenames Vanderpool and Pacifica. They allow a single machine to run multiple operating systems at once without incurring significant emulation costs. ... The Power Architecture logo Power Architecture is a broad term to describe similar instruction sets for RISC microprocessors developed and manufactured by such companies as IBM, Freescale, AMCC, Tundra and P.A. Semi. ...

References

For historical sources, including many seminal computer science papers dealing with the topic, see CP/CMS references. Information technology (IT), as defined by the Information Technology Association of America (ITAA)is: the study, design, development, implementation, support or management of computer-based information systems, particularly software applications and computer hardware. ... VM/CMS (Virtual Machine/Conversational Monitor System, originally called CP/CMS when it first appeared) is an IBM system used on System/360, System/370, System/390 and zSeries IBM mainframes. ...

See also

• AMD-V
• Application Virtualization
• Comparison of Application Virtual Machines
• Comparison of virtual machines
• Emulation
• History of CP/CMS
• Hypervisor
• IBM M44/44X
• IBM SAN Volume Controller
• Intel-VT
• Nanokernel
• Operating system-level virtualization
• Physical-to-Virtual
• Virtualization Development
• Virtual machine monitor
• Virtual Tape Library
• X86 virtualization — hardware-assisted virtualization
• Interconnect Driven Server
• IT Resource Governance
• Desktop Virtualization
• Storage Virtualization

x86 virtualization is the method by which the x86 processor architecture is virtualized. ... Application Virtualization is a field within computer science which deals with breaking the age old bond between physical hardware, operating system, and the program which runs on top of them. ... This comparison of Application Virtual Machines lists some of the common software virtual machines that implement the concept of Application Virtualization, typically for the purpose allowing application binaries to be portably run on many different computer architectures and operating systems. ... The table below compares basic information about virtual machine packages, including: creator, guest systems supported, license, etc. ... This article is about emulation in computer science. ... This lengthy article explores the History of CP/CMS – the historical context in which this important IBM time-sharing operating system was built. ... A hypervisor in computing is a scheme which allows multiple operating systems to run, unmodified, on a host computer at the same time. ... The IBM M44/44X was an experimental computer system from the mid 1960s, designed and operated at IBMs Thomas J. Watson Research Center at Yorktown Heights, New York. ... The IBM San Volume Controller (SVC) is a block storage virtualization appliance. ... x86 virtualization is the method by which x86-based guest operating systems are run under another host x86 operating system, with little or no modification of the guest OS. The x86 processor architecture did not originally meet the Popek and Goldberg virtualization requirements. ... In computer science, a nanokernel or picokernel is a very minimalist operating system kernel. ... Operating System Virtualization is a server virtualization technology which virtualizes servers on an operating system (kernel) layer. ... Also known as P2V Physical-to-Virtual describes the process of decoupling and migrating a physical servers OS, applications, and data from a physical server to a virtual machine guest hosted on a virtualization platform. ... // Timelines 1960 IBM Sun Hewlett-Packard 1999 February 8, 1999, VMware introduced VMware Virtual Platform. ... In general terms, a virtual machine in computer science is software that creates an environment between the computer platform and the end user in which the end user can operate software. ... Virtual Tape Library (VTL) is a data storage virtualization technology used typically for archival storage purposes. ... x86 virtualization is the method by which x86-based guest operating systems are run under another host x86 operating system, with little or no modification of the guest OS. The x86 processor architecture did not originally meet the Popek and Goldberg virtualization requirements. ... There are very few or no other articles that link to this one. ... Storage Virtualization refers to the process of completely abstracting logical storage from physical storage. ...

External links

This article or section may contain spam. Wikipedia spam consists of external links mainly intended to promote a website. Wikipedia spam also consists of external links to websites which primarily exist to sell goods or services, use objectionable amounts of advertising, or require payment to view the relevant content. If you are familiar with the content of the external links, please help by removing promotional links in accordance with Wikipedia:External links. (You can help!)

• Virtualization Video for Admins and Managers - A 19 minutes video on virtualization by
• What is virtualization? - ZDNet Whiteboard webcast about virtualization.
• An introduction to Virtualization A very good article examining the history of virtualization and its current status.
• The Effect of Virtualization on OS Interference in PDF format.
• Linux Virtualization Software
• Latest Virtualization News & Support Resources
• Debate: Virtualization - will it change the way we use servers forever? - Video

Skeptics about recent virtualization trends

• Virtualization Limitations
• Grid computing skeptic