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Hardware-assisted Virtualization
In computing, hardware-assisted virtualization is a platform virtualization approach that enables efficient full virtualization using help from hardware capabilities, primarily from the host processors. A full virtualization is used to emulate a complete hardware environment, or virtual machine, in which an unmodified guest operating system (using the same instruction set as the host machine) effectively executes in complete isolation. Hardware-assisted virtualization was added to x86 processors (Intel VT-x, AMD-V or VIA VT) in 2005, 2006 and 2010 (respectively). Hardware-assisted virtualization is also known as accelerated virtualization; Xen calls it hardware virtual machine (HVM), and Virtual Iron calls it native virtualization. History Hardware-assisted virtualization first appeared on the IBM System/370 in 1972, for use with VM/370, the first virtual machine operating system. With the increasing demand for high-definition computer graphics (e.g. CAD), virtualization o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, engineering, mathematical, technological and social aspects. Major computing disciplines include computer engineering, computer science, cybersecurity, data science, information systems, information technology and software engineering. The term "computing" is also synonymous with counting and calculating. In earlier times, it was used in reference to the action performed by mechanical computing machines, and before that, to human computers. History The history of computing is longer than the history of computing hardware and includes the history of methods intended for pen and paper (or for chalk and slate) with or without the aid of tables. Computing is intimately tied to the representation of numbers, though mathematical conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Power Systems
Power Systems is a family of server computers from IBM that are based on its Power processors. It was created in 2008 as a merger of the System p and System i product lines. History IBM had two distinct POWER- and PowerPC-based hardware lines since the early 1990s: * Servers running processors based on the IBM PowerPC-AS architecture in the AS/400 family (later known as iSeries, then System i) running OS/400 (later known as i5/OS, and now IBM i) * Servers and workstations using POWER and PowerPC processors in the RS/6000 family (later known as pSeries, then System p), running IBM AIX and Linux on Power. After the introduction of the POWER4 processor in 2001, there was little difference between both the "p" and the "i" hardware; the only differences were in the software and services offerings. With the introduction of the POWER5 processor in 2004, even the product numbering was synchronized. The ''System i5 570'' was virtually identical to the ''System p5 570''. In Apr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VirtualBox
Oracle VM VirtualBox (formerly Sun VirtualBox, Sun xVM VirtualBox and Innotek VirtualBox) is a type-2 hypervisor for x86 virtualization developed by Oracle Corporation. VirtualBox was originally created by Innotek GmbH, which was acquired by Sun Microsystems in 2008, which was in turn acquired by Oracle in 2010. VirtualBox may be installed on Microsoft Windows, macOS, Linux, Solaris and OpenSolaris. There are also ports to FreeBSD and Genode. It supports the creation and management of guest virtual machines running Windows, Linux, BSD, OS/2, Solaris, Haiku, and OSx86, as well as limited virtualization of guests on Apple hardware. For some guest operating systems, a "Guest Additions" package of device drivers and system applications is available, which typically improves performance, especially that of graphics, and allows changing the resolution of the guest OS automatically when the window of the virtual machine on the host OS is resized. Released under the terms of the GN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Translation
In computing, binary translation is a form of binary recompilation where sequences of instructions are translated from a ''source'' instruction set to the ''target'' instruction set. In some cases such as instruction set simulation, the target instruction set may be the same as the source instruction set, providing testing and debugging features such as instruction trace, conditional breakpoints and hot spot detection. The two main types are static and dynamic binary translation. Translation can be done in hardware (for example, by circuits in a CPU) or in software (e.g. run-time engines, static recompiler, emulators). Motivation Binary translation is motivated by a lack of a binary for a target platform, the lack of source code to compile for the target platform, or otherwise difficulty in compiling the source for the target platform. Statically-recompiled binaries run potentially faster than their respective emulated binaries, as the emulation overhead is removed. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network World
International Data Group (IDG, Inc.) is a market intelligence and demand generation company focused on the technology industry. IDG, Inc.’s mission is centered around supporting the technology industry through research, data, marketing technology, and insights that help create and sustain relationships between businesses. IDG, Inc. is wholly owned by Blackstone and is led by Mohamad Ali, who was appointed CEO of the company in 2019. Ali serves on IDG, Inc.’s leadership team along with IDC President Crawford Del Prete, IDG, Inc.’s Chief Financial Officer Donna Marr, and Foundry President Kumaran Ramanathan. IDG, Inc. is headquartered in Needham, MA and is parent company to both International Data Corporation (IDC) and Foundry (formerly IDG Communications). History International Data Group was initially founded as International Data Corporate (IDC) in 1964 by Patrick Joseph McGovern, shortly after he had graduated from the Massachusetts Institute of Technology (MIT). Bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Privilege (computing)
In computing, privilege is defined as the delegation of authority to perform security-relevant functions on a computer system. A privilege allows a user to perform an action with security consequences. Examples of various privileges include the ability to create a new user, install software, or change kernel functions. Users who have been delegated extra levels of control are called privileged. Users who lack most privileges are defined as unprivileged, regular, or normal users. Theory Privileges can either be automatic, granted, or applied for. An automatic privilege exists when there is no requirement to have permission to perform an action. For example, on systems where people are required to log into a system to use it, logging out will not require a privilege. Systems that do not implement file protection - such as MS-DOS - essentially give unlimited privilege to perform any action on a file. A granted privilege exists as a result of presenting some credential to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trap (computing)
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an ''interrupt handler'' (or an ''interrupt service routine'', ISR) to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error. Interrupts are commonly used by hardware devices to indicate electronic or physical state changes that require time-sensitive attention. Interrupts are also commonly used to implement computer multitasking, especially in real-time computing. Systems that use interrupts in these ways are said to be interrupt-driven. Types Interrupt signals may be issued in response to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypervisor
A hypervisor (also known as a virtual machine monitor, VMM, or virtualizer) is a type of computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a ''host machine'', and each virtual machine is called a ''guest machine''. The hypervisor presents the guest operating systems with a virtual operating platform and manages the execution of the guest operating systems. Unlike an emulator, the guest executes most instructions on the native hardware. Multiple instances of a variety of operating systems may share the virtualized hardware resources: for example, Linux, Windows, and macOS instances can all run on a single physical x86 machine. This contrasts with operating-system–level virtualization, where all instances (usually called ''containers'') must share a single kernel, though the guest operating systems can differ in user space, such as different Linux distributions with the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popek And Goldberg Virtualization Requirements
The Popek and Goldberg virtualization requirements are a set of conditions sufficient for a computer architecture to support system virtualization efficiently. They were introduced by Gerald J. Popek and Robert P. Goldberg in their 1974 article "Formal Requirements for Virtualizable Third Generation Architectures". Even though the requirements are derived under simplifying assumptions, they still represent a convenient way of determining whether a computer architecture supports efficient virtualization and provide guidelines for the design of virtualized computer architectures. VMM definition System virtual machines are capable of virtualizing a full set of hardware resources, including a processor (or processors), memory and storage resources and peripheral devices. A virtual machine monitor (VMM, also called hypervisor) is the piece of software that provides the abstraction of a virtual machine. There are three properties of interest when analyzing the environment created by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud Computing
Cloud computing is the on-demand availability of computer system resources, especially data storage ( cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over multiple locations, each of which is a data center. Cloud computing relies on sharing of resources to achieve coherence and typically uses a "pay as you go" model, which can help in reducing capital expenses but may also lead to unexpected operating expenses for users. Value proposition Advocates of public and hybrid clouds claim that cloud computing allows companies to avoid or minimize up-front IT infrastructure costs. Proponents also claim that cloud computing allows enterprises to get their applications up and running faster, with improved manageability and less maintenance, and that it enables IT teams to more rapidly adjust resources to meet fluctuating and unpredictable demand, providing burst computing capability: high computing p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LPAR
A logical partition (LPAR) is a subset of a computer's hardware resources, virtualized as a separate computer. In effect, a physical machine can be partitioned into multiple logical partitions, each hosting a separate instance of an operating system. PR/SM Although the terms ''PR/SM'' and ''LPAR'' are often used interchangeably in IBM Z, including in IBM documentation, ''PR/SM'' was not present in the IBM 370/168's Virtual Machine Facility/370; it came in with the IBM 3090, years later. Formally, LPAR designates the mode of operation or an individual logical partition, whereas PR/SM is the commercial designation of the feature. In mainframe computing PR/SM (Processor Resource/System Manager) is a type-1 Hypervisor (a virtual machine monitor) that allows multiple logical partitions to share physical resources such as CPUs, I/O channels and LAN interfaces; when sharing channels, the LPARs can share I/O devices such as direct access storage devices (DASD). PR/SM is integrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System Z
IBM Z is a family name used by IBM for all of its z/Architecture mainframe computers. In July 2017, with another generation of products, the official family was changed to IBM Z from IBM z Systems; the IBM Z family now includes the newest model, the IBM z16, as well as the z15, the z14, and the z13 (released under the IBM z Systems/IBM System z names), the IBM zEnterprise models (in common use the zEC12 and z196), the IBM System z10 models (in common use the z10 EC), the IBM System z9 models (in common use the z9EC) and ''IBM eServer zSeries'' models (in common use refers only to the z900 and z990 generations of mainframe). Architecture The ''zSeries,'' ''zEnterprise,'' ''System z'' and ''IBM Z'' families were named for their availability – ''z'' stands for High availability, zero downtime. The systems are built with spare components capable of hot Failover, failovers to ensure continuous operations. The IBM Z family maintains full backward compatibility. In effect, curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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