Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device or network resources. It allows a single physical resource (such as a server, operating system, application, or storage device) to function as multiple logical resources. It is the process of abstracting computing resources such that multiple operating system and application images can share a single physical server, bringing significant cost-of-ownership and manageability benefits.
It is a combination of software and hardware engineering that creates Virtual Machines (VMs) – an abstraction of the computer hardware that allows a single machine to act as if it where many machines.
Virtualization allows users to consolidate physical resources, simplify deployment and administration, and reduce power and cooling requirements. While virtualization technology is most popular in the server world, virtualization technology is also being used in data storage such as Storage Area Networks, and inside of operating systems such as Windows Server 2008 with Hyper-V.
The virtualization software is used to “virtualize” the hardware resources of an x86-based computer including the CPU, RAM, hard disk and network controller—to create a fully functional virtual machine that can run its own operating system and applications just like a “real” computer. Each virtual machine contains a complete system, eliminating potential conflicts. It works by inserting a thin layer of software directly on the computer hardware or on a host operating system. This contains a virtual machine monitor (VMM) or “hypervisor” that allocates hardware resources dynamically and transparently. Multiple operating systems run concurrently on a single physical computer and share hardware resources with each other. By encapsulating an entire machine, including CPU, memory, operating system, and network devices, a virtual machine is completely compatible with all standard x86 operating systems, applications, and device drivers. You can safely run several operating systems and applications at the same time on a single computer, with each having access to the resources it needs when it needs them.
To virtualize a given computer, a piece of software called a virtual machine monitor (VMM) must be installed. This software is also commonly referred to as a hypervisor. After this VMM software is installed, individual virtual computers (called virtual machines or VMs) can be run on the same hardware. Note that each virtual machine can run its own operating system, applications, etc. – the goal is to make each VM act like a standalone machine would.
There are different types Virtualization which are discussed as follows:-
- Operating system virtualization is the use of software to allow a piece of hardware to run multiple operating system images at the same time.
- Network virtualization is a method of combining the available resources in a network by splitting up the available bandwidth into channels. Each channel can be assigned (or reassigned) to a particular server or device in real time.
- Storage virtualization is the pooling of physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. Storage virtualization is commonly used in storage area networks. Storage Area Networks (SANs) are usually connected to servers via Fibre Channel or other high-speed link, allowing storage performance to equal direct-attach storage. SANs or other network-based storage systems are key components for server virtualization.
- Application virtualization. An application is isolated from the underlying operating system by means of wrapper software that encapsulates it. This allows multiple applications that may have conflicting dynamic link libraries (DLLs) or other incompatibilities to run on the same machine without affecting each other.
- Desktop virtualization. This is similar to server software virtualization, but it runs on client systems such as Windows® 7 and Windows Vista®.
- Server hardware virtualization. Also known as a hypervisor, server hardware virtualization runs a very lightweight core operating system. The hypervisor can host independent virtual machines (VMs)
- Server software virtualization. An operating system, such as Windows Server® 2003 or Windows Server 2008 R2, runs an application that is able to host VMs. Each VM runs a completely separate operating system and application set.
The advantages of virtualization include:
- Server consolidation: If applications running on separate computers do not utilize the computing resources of their computers, they can be consolidated onto a smaller number of servers using virtualization technology.
- Smaller footprint: Virtualizing servers decreases the number of physical boxes that a company must use. This means a smaller datacenter, with the resulting decreases in cooling and electrical costs.
- Hardware costs: Because virtualization allows for greater utilization of existing resources, fewer physical servers are required, saving money both on upfront hardware costs and and on maintenance costs.
- Ease of Testing and Development: Virtualization speeds up the development and testing process because it makes it easier to create different operating system environments. Virtualization allows designers to compare application performance across different operating environments, as well testing out applications in virtual environments.
The problem of global warming can be tackled easily by arranging corporate meets which creates an added incentive for virtualization. As server workloads differ, virtualization provides the ability for virtual machines that are over utilizing the resources of a server to be moved to underutilized servers. This dynamic load balancing creates efficient utilization of server resources. Software security is also provided. Hence, most of the areas are covered by Virtualization.
Data duplication is completely terminated as data exists on every user’s hard drive in the form of exchange archive files, or .pst. The Bottom Line Virtualization and Cloud Computing pour a lot of opportunities for businesses to utilize technology in an effective way. Problems like under utilization, high hardware costs and poor system availability are completely nullified by the use of Virtualization. Therefore, it proves to be a boon especially for the corporate sector.
Seamless transitions between different operating systems add to the advantages of Virtualization. But nothing is perfect. Virtualization is also tainted with some flaws. The most documented side effect to date, virtual server sprawl results from the combination of ease of deployment and lack of life-cycle management of virtual machines. But despite these follies, Virtualization has managed to attract users worldwide. It is to be seen if Virtualization can tackle the flaws before it is too late.
Thanks to Ms. Ulka for this article
Posted by Bestsolver