What is Server virtualization?
Server virtualization is a technique where one or more virtualized server instances, such as physical machines, processors, or operating systems, are created and abstracted on a single server. This approach reduces resource consumption and costs by placing a hypervisor on top of a computer, which organizes and manages these virtual equivalents of physical resources. This process creates virtual machines (VMs) capable of acting as independent servers, reducing the need for individual applications.
It relies on how resources are used. Hypervisor-managed virtualization can create and run many VMs simultaneously, allowing one computer to handle many workloads simultaneously. Thus, it reduces server counts and data center pressure, increases IT versatility, and reduces IT costs. However, while virtualization offers many benefits, issues like licensing, management complexity, and potential availability and downtime challenges can blunt some of its advantages.
To successfully adopt and deploy virtualization throughout the data center, organizations need to understand what virtualization is, how it works, the tradeoffs associated with it, and its use cases.
How Does Server Virtualization Work?
For server virtualization to work, virtual software must be created, and that software is called a hypervisor. “A hypervisor is a software layer responsible for interposition between the virtual, or digital, elements and the physical pieces of hardware (processors, CPU, RAM, etc.) that contribute to the functioning of the virtualized infrastructure.
Following the installation of the hypervisor on the primary device, the virtualization software, such as Proxmox VE, will then be utilized to emulate each physical resource and create a new virtual server on it. It may replace an individual physical server or the entire stack of many physical servers. Hypervisor software creates and runs multiple VMs as well. Such virtualization has certain adjustments based on the client’s requirement – hence, they can be grouped under it.
Core Concepts of Server Virtualization
This technology’s core is server virtualization, which enables multiple instances of a virtual machine (VM) to operate on a single physical server. It allows for optimized resource utilization, flexibility, and scalability, which are essential for modern IT environments. The five key concepts of server virtualization are as follows:
Virtual Machines (VMs)
A VM (Virtual Machine) is a software implementation of a physical computer, with its own OS and applications. Different VM types can be run since each one is isolated from others, meaning that it runs independently with its specific configuration, OS, and resources (CPU, memory, storage). VMs are run on a physical server (host), which offers flexibility and resource optimization.
Hypervisor
This software layer creates and controls the VM; that software layer is called a hypervisor. The hypervisor serves as a mediator between the physical hardware and the VMs, distributing resources such as CPU, memory, and storage to the VMs. There are two categories of hypervisors:
- Type 1 (Bare-metal): This type of software installs natively on the physical server, with no host operating system required (e.g., VMware ESXi, Microsoft Hyper-V).
- Type 2 (Hosted): This type of virtualization runs on top of an already installed host operating system (such as VMware Workstation or Oracle VirtualBox).
Resource Pooling
Resource pooling refers to aggregating physical resources (CPU, RAM, storage) from multiple servers into a shared virtualized environment. This allows VMs to access these resources dynamically, optimizing utilization and reducing waste. Resource pooling provides greater flexibility, scalability, and cost efficiency since the resources can be distributed across multiple VMs based on demand.
Isolation and Security
A virtualized environment consists of multiple VMs running in isolation to avoid impacting the performance or security of one VM on another. By keeping every single VM isolated, the rest of the VMs on the host will not be affected by a crash or security breach of one VM. This also allows separate VMs to have differing configurations, security policies, and operating systems.
Live Migration
Live migration moves a running VM from one physical host to another with zero downtime. This feature is critical for load balancing, hardware repair, and reducing downtime. It allows workloads to be reallocated between servers in real time, maximizing resource use and maintaining service availability.
The Benefits of Server Virtualization
This provides a complete technology and considerable business benefits to the organization. Here are a few of the key and shared benefits of virtualization:
Reduced Hardware and Facilities Costs
Server consolidation reduces both the hardware costs of your data center and the costs of the facilities themselves — less power and cooling , for example. Virtualization server consolidation is a significant cost saver for organizations with a high server count and was one of the main reasons for early virtualization adoption through the 2000s.
Server Consolidation
Virtualization allows one physical server to perform the work of many servers, thus reducing the number of servers in the enterprise. That process is known as server consolidation.
Consider the following:
Today, you have 12 physical servers, each running a single application. With virtualization, we can host 3 VMs on a physical server; each VM might run one application. With this change, the organization would need four physical servers to run the same 12 workloads.
Greater Server Versatility
Since each VM is its own standalone instance, it has to run an independent OS. However, the OS can differ among VMs, allowing the organization to run whatever blend of Windows, Linux, and other OSes it wishes on the same physical hardware. This kind of flexibility is unavailable with physical servers.
Simplified Physical Infrastructure
With fewer servers present, the number of racks and cables in the data center is significantly decreased. This streamlines deployments and troubleshooting. The organization is able to achieve the same computing goals in just a fraction of the space, power, and cooling space compared to the physical server complement.
Improved Management
You have centralized control of your resources and the creation of VM instances. New virtualization adds a whole new horsepower of tooling and functionality, enabling IT admins to oversee and control the virtualized stack. For example, the live migration feature allows moving a VM across two physical servers so that the workload does not stop.
Features that protect the data, like snapshots, can record the condition of a VM at any instance in time so that the VM can be restored quickly and easily from any unanticipated faults or disasters. Virtualization is conducive to central management, so admins can view all the VMs in the environment and deploy patches or updates with a reduced possibility of making mistakes.
Final Words
Ultimately, the advantages of server virtualization have made a lasting impact on IT infrastructure management. Virtualization abstracts physical hardware and allows multiple virtual instances to run on one server, improving scalability, security, and manageability. That said, knowing the core concepts of the tech —VMS, hypervisors, resource pooling, isolation, and live migration — and what the tradeoffs are is essential to successfully implementing it.
In theory, server virtualization is a well-established technology to establish business operations, optimize hardware infrastructure, and enhance performance in an IT environment.
Priya Mervana
Verified Web Security Experts
Priya Mervana is working at SSLInsights.com as a web security expert with over 10 years of experience writing about encryption, SSL certificates, and online privacy. She aims to make complex security topics easily understandable for everyday internet users.