Virtualization, in computing, means creating a virtual (rather than actual) version of something, like to create a virtual computer hardware platform, operating system (OS), storage device, or computer network resources, etc.
Virtualization started with 1960's mainframes, during which it was a method of logically dividing the mainframes' resources for several different applications running on it.
In short Virtualization software solves the problem by enabling several operating systems and applications to run on one physical server or “host.” Each self-contained “virtual machine” is isolated from the others, and uses as much of the host’s computing resources as it requires.
Hardware virtualization or platform virtualization refers to the creating virtual machine(s) that acts like a real computer with an operating system. Software executed on these virtual machines is separated from the underlying hardware resources. For example, a computer that is running Microsoft Windows Server 2008 R2 may host a virtual machine that looks like a computer with the Ubuntu Linux operating system; Ubuntu-based software can be run on the virtual machine.
In hardware virtualization, the host machine is the actual machine on which the virtualization takes place, and the guest machine is the virtual machine. The words host and guest are used to distinguish the software that runs on the physical machine from the software that runs on the virtual machine. The software or firmware that creates a virtual machine on the host hardware is called a hypervisor or Virtual Machine Manager.
Types of Hardware Virtualization:
The different types of hardware virtualization are as follows:
1) Full virtualization: Almost complete simulation of the actual hardware to allow software, which typically consists of a guest operating system, to run unmodified.
2) Partial virtualization: Some but not all of the target environment is simulated. Some guest programs, therefore, may need modifications to run in this virtual environment.
Paravirtualization: A hardware environment is not simulated; however, the guest programs are executed in their own isolated domains, as if they are running on a separate system. Guest programs need to be specifically modified to run in this environment.
3) Hardware-assisted virtualization is a way of improving the efficiency of hardware virtualization. It involves employing specially designed CPUs and hardware components that help improve the performance of a guest environment.
Hardware virtualization can be viewed as part of an overall trend in enterprise I.T. 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 goal of virtualization is to centralize administrative tasks while improving scalability and overall hardware-resource utilization.
With virtualization, several operating systems can be run in parallel on a single central processing unit (CPU). This parallelism tends to reduce overhead costs and differs from multitasking, which involves running several programs on the same OS. Using virtualization, an enterprise can better manage updates and rapid changes to the operating system and applications without disrupting the user.
Virtualization dramatically improves the efficiency and availability of resources and applications in an organization. The old model of one server, one operating system that leads to under utilized resource, with virtual resources we can achive one server and may operating systems and achive best utilization of hardware resources.
Hardware virtualization is not the same as hardware emulation. In hardware emulation, a piece of hardware imitates another, while in hardware virtualization, a hypervisor (a piece of software) imitates a particular piece of computer hardware or the entire computer.The hypervisor is not the same as an emulator; both are computer programs that imitate hardware, but their domain of use in language differs.
Virtualization started with 1960's mainframes, during which it was a method of logically dividing the mainframes' resources for several different applications running on it.
In short Virtualization software solves the problem by enabling several operating systems and applications to run on one physical server or “host.” Each self-contained “virtual machine” is isolated from the others, and uses as much of the host’s computing resources as it requires.
Hardware virtualization or platform virtualization refers to the creating virtual machine(s) that acts like a real computer with an operating system. Software executed on these virtual machines is separated from the underlying hardware resources. For example, a computer that is running Microsoft Windows Server 2008 R2 may host a virtual machine that looks like a computer with the Ubuntu Linux operating system; Ubuntu-based software can be run on the virtual machine.
In hardware virtualization, the host machine is the actual machine on which the virtualization takes place, and the guest machine is the virtual machine. The words host and guest are used to distinguish the software that runs on the physical machine from the software that runs on the virtual machine. The software or firmware that creates a virtual machine on the host hardware is called a hypervisor or Virtual Machine Manager.
Types of Hardware Virtualization:
The different types of hardware virtualization are as follows:
1) Full virtualization: Almost complete simulation of the actual hardware to allow software, which typically consists of a guest operating system, to run unmodified.
2) Partial virtualization: Some but not all of the target environment is simulated. Some guest programs, therefore, may need modifications to run in this virtual environment.
Paravirtualization: A hardware environment is not simulated; however, the guest programs are executed in their own isolated domains, as if they are running on a separate system. Guest programs need to be specifically modified to run in this environment.
3) Hardware-assisted virtualization is a way of improving the efficiency of hardware virtualization. It involves employing specially designed CPUs and hardware components that help improve the performance of a guest environment.
Hardware virtualization can be viewed as part of an overall trend in enterprise I.T. 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 goal of virtualization is to centralize administrative tasks while improving scalability and overall hardware-resource utilization.
With virtualization, several operating systems can be run in parallel on a single central processing unit (CPU). This parallelism tends to reduce overhead costs and differs from multitasking, which involves running several programs on the same OS. Using virtualization, an enterprise can better manage updates and rapid changes to the operating system and applications without disrupting the user.
Virtualization dramatically improves the efficiency and availability of resources and applications in an organization. The old model of one server, one operating system that leads to under utilized resource, with virtual resources we can achive one server and may operating systems and achive best utilization of hardware resources.
Hardware virtualization is not the same as hardware emulation. In hardware emulation, a piece of hardware imitates another, while in hardware virtualization, a hypervisor (a piece of software) imitates a particular piece of computer hardware or the entire computer.The hypervisor is not the same as an emulator; both are computer programs that imitate hardware, but their domain of use in language differs.
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