Any discussion of cloud computing typically begins with virtualization. Virtualization is using computer resources to imitate other computer resources or whole computers. It separates resources and services from the underlying physical delivery environment.
Virtualization is the process of creating a software-based (or virtual) representation of something rather than a physical one. Virtualization can apply to applications, servers, storage, and networks and is the single most effective way to reduce IT expenses while boosting efficiency and agility for all size businesses.
In other words, Virtualization is a technique, which allows to share a single physical instance of a resource or an application among multiple customers and organizations. It does by assigning a logical name to a physical storage and providing a pointer to that physical resource when demanded.
HOW VIRTUALIZATION WORKS
IT organizations are challenged by the limitations of today’s x86 servers, which are designed to run just one operating system and application at a time. As a result, even small data centres have to deploy many servers, each operating at just 5 to 15 percent of capacity—highly inefficient by any standard.
Virtualization uses software to simulate the existence of hardware and create a virtual computer system. Doing this allows businesses to run more than one virtual system – and multiple operating systems and applications — on a single server.
It describes a technology in which an application, guest operating system or data storage is abstracted away from the true underlying hardware or software. A key use of virtualization technology is server virtualization, which uses a software layer called a hypervisor to emulate the underlying hardware. This often includes the CPU’s memory, I/O and network traffic. The guest operating system, normally interacting with true hardware, is now doing so with a software emulation of that hardware, and often the guest operating system has no idea it’s on virtualized hardware. While the performance of this virtual system is not equal to the performance of the operating system running on true hardware, the concept of virtualization works because most guest operating systems and applications don’t need the full use of the underlying hardware. This allows for greater flexibility, control and isolation by removing the dependency on a given hardware platform. While initially meant for server virtualization, the concept of virtualization has spread to applications, networks, data and desktops.
To understand how virtualization helps with cloud computing, you must understand its many forms. In essence, in all cases, a resource actually emulates or imitates another resource. Here are some examples:
The Virtual Machine
A virtual computer system is known as a “virtual machine” (VM): a tightly isolated software container with an operating system and application inside. Each self-contained VM is completely independent. Putting multiple VMs on a single computer enables several operating systems and applications to run on just one physical server, or “host”.
A thin layer of software called a hypervisor decouples the virtual machines from the host and dynamically allocates computing resources to each virtual machine as needed.
Key Properties of Virtual Machines
VMs have the following characteristics, which offer several benefits.
- Run multiple operating systems on one physical machine
- Divide system resources between virtual machines
- Provide fault and security isolation at the hardware level
- Preserve performance with advanced resource controls
- Save the entire state of a virtual machine to files
- Move and copy virtual machines as easily as moving and copying files
- Provision or migrate any virtual machine to any physical server
Companies have built software that can emulate a whole computer. That way, one computer can perform as though it were actually 20 computers. The application consolidation results can be quite significant. For example, you might be able to move from a data centre with thousands of servers to one that supports as few as a couple of hundred. This reduction results in less money spent not only on computers, but also on power, air conditioning, maintenance, and floor space.
Types of Virtualization
- Hardware Virtualization.
- Operating system Virtualization.
- Server Virtualization.
- Storage Virtualization.
1) Hardware Virtualization:
When the virtual machine software or virtual machine manager (VMM) is directly installed on the hardware system is known as hardware virtualization.
The main job of hypervisor is to control and monitoring the processor, memory and other hardware resources.
After virtualization of hardware system we can install different operating system on it and run different applications on those OS.
Hardware virtualization is mainly done for the server platforms, because controlling virtual machines is much easier than controlling a physical server.
2) Operating System Virtualization:
When the virtual machine software or virtual machine manager (VMM) is installed on the Host operating system instead of directly on the hardware system is known as operating system virtualization.
Operating System Virtualization is mainly used for testing the applications on different platforms of OS.
3) Server Virtualization:
When the virtual machine software or virtual machine manager (VMM) is directly installed on the Server system is known as server virtualization.
Server virtualization is done because a single physical server can be divided into multiple servers on the demand basis and for balancing the load.
4) Storage Virtualization:
Storage virtualization is the process of grouping the physical storage from multiple network storage devices so that it looks like a single storage device.
Storage virtualization is also implemented by using software applications.
Storage virtualization is mainly done for back-up and recovery purposes.
Benefits of Virtualization
Virtualization can increase IT agility, flexibility, and scalability while creating significant cost savings. Workloads get deployed faster, performance and availability increases and operations become automated, resulting in IT that’s simpler to manage and less costly to own and operate. Additional benefits include:
- Reduce capital and operating costs.
- Minimize or eliminate downtime.
- Increase IT productivity, efficiency, agility and responsiveness.
- Provision applications and resources faster.
- Enable business continuity and disaster recovery.
- Simplify data centre management.
- Build a true Software-Defined Data Centre
Now that virtualization is a mature technology, organizations should be looking to further refine their infrastructure and consider the next step.
Offlate we no longer hear the call to virtualize all things, not because we stopped liking virtualization, but because many have already done so. The physical-to-virtual migration tool sits idle; there are no more piles of hardware to remove from the data center. Virtualization brought something to the table for everyone and it was incredibly successful. So the question becomes, now what?
Now that virtualization levels have stabilized, what is next? To some, the hypervisor is a commodity as focus has shifted to DevOps, cloud, networking, automation and other groups. While all of these have value to different business types and segments, there is still one focus that is common to all businesses and segments: security.
Server virtualization faces competition from both cloud methodologies and containers. With most companies planning for hybrid cloud installations, or even a move to software as a service, the need for cloud-based alternatives to traditional hypervisor virtualization is being addressed by OpenStack and — to a lesser extent — by Microsoft’s Azure stack packaged onto inexpensive hardware.
Container use is growing rapidly and acceptance is occurring much faster than the cloud. With a robust tool infrastructure becoming available, this is clearly a major threat to the ongoing need for hypervisors.
This, along with the cloud, suggests that hypervisor virtualization has peaked.Everyone is looking to monetize on the advantages of cloud. Be it private, public or some kind of hybrid approach.