Virtualization

A physical server is a piece of data center hardware that includes computing, memory, storage, and network interface components. These servers are deployed in-house and come in multiple form factors such as blades, racks, and towers.

Virtualization takes the properties of a physical server and abstracts them into multiple virtual entities. It emulates the function and performance of physical infrastructure using a software-based abstraction layer.

In a traditional physical server (sometimes referred to as a bare metal server when dedicated to a single customer) all components are tied to a single piece of hardware and are often used inefficiently. Many organizations have more server space than they actually use, and very little workload on these systems uses all the capacity and throughput of a processor.

Virtualization makes it possible for individual workloads and tasks to run more efficiently because they are not directly tied to a particular piece of hardware. Virtual servers still need hardware to exist, but availability/capacity is much more flexible and is often defined by the needs of the organization rather than hardware limitations.

Data center virtualization happens when all servers are abstracted to create a fully virtualized ecosystem. This enables organizations to run application workloads on a set of server assets completely independent of the underlying physical server hardware. A healthy virtualized infrastructure maximizes CPU utilization and reliability of worker workloads.

3 Types of Server Virtualization Approaches

At a high level, all virtualization technologies aim to achieve the same goal: to optimize physical server availability by dividing resources and enabling them to be provisioned more agile. The specific approach to virtualization depends on the needs and limitations of the organization targeting virtualization.

• Full virtualization leverages a hypervisor to create and maintain fully autonomous VMs that do not need to be modified to work with different operating systems. This can be done with a software-assisted approach, but hardware-assisted full virtualization has become the dominant approach since Intel and AMD created new x86 CPU expansions in the mid-2000s. Microsoft Hyper-V, Oracle VM VirtualBox, and VMware vSphere are among the leading full virtualization products.
• Para virtualization uses an application programming interface (API) to send hypercalls between the hypervisor and operating systems. This means that each VM can communicate and be aware of each other to share resources. Sometimes simply referred to as PV, paravirtualization can run on system architectures that do not support hardware-assisted virtualization. Most products that enable full virtualization also enable paravirtualization.
• OS-level virtualization happens without a hypervisor. Instead, the physical server’s operating system includes a virtualization capability that acts like a hypervisor to create multiple user environments called containers. Oracle Solaris is one of the premier operating system-level virtualization products.

What are Server Virtualization Softwares?

As server virtualization continues to grow in data centers around the world, many software vendors have become giants in the virtualization market. These virtualization software are:

-> Vmware
-> Hyper-V (microsoft)
-> Red Hat Virtualization
-> Oracle VM VirtualBox
-> Citrix Hypervisor
-> Proxmox VE
-> IBM PowerVM
-> Virtuozzo