Virtualization, what does it mean?

So you’ve rented a powerful dedicated server or a cloud server from Neterra.Cloud, and you want to make sure its being fully utilized. So, why not use server virtualization? Server virtualization is a solution that can lower the need for multiple powerful devices to just one and you can use it for various tasks and under different operating systems. If this is a new topic for you and you’re interested in learning more – read on to discover server virtualization! 

What is server virtualization? 

Virtualization is a technology that lets you use your hardware for various purposes at the same time by creating virtual servers, also called virtual machines (VMs), on different layers. You only have one physical server, but you can run multiple virtual servers within it. Every virtual server will operate as an independent instance. Imagine the following situation – you need three servers – a data server, a mail server, and a web server. Without virtualization, you will need three separate devices if you want them to work separately, but with it you can have all the servers in the same device, sharing its resources, and yet they can be virtually separated (independent). 

History of server virtualization 

The history of server virtualization can be traced back to the 1960s. Bell Labs, General Electric (GE), and International Business Machines (IBM) were pioneers developing this technology. 

During the early 1960s, IBM maintained a diverse array of systems, with each succeeding generation significantly differing from its predecessor. This diversity posed challenges for customers in adapting to the evolving features and demands of each new system. Additionally, computers were limited to performing only one task at a time, requiring users to execute processes in batches when faced with multiple tasks. 

In the 1970s, IBM’s VM/370 was developed allowing IBM mainframes to run multiple operating systems simultaneously. 

The early virtualization was in the form of hypervisors, usually used for payroll. They could perform routine tasks quickly and repeatedly. In the 1990s many of the enterprises had physical servers and used software from a single vendor. Each server could run just one vendor-specific task, and was unable to run legacy applications. 

At this point, server virtualization solved the two problems: It could run legacy applications and various OSes simultaneously. 

The development of server virtualization was essential for cloud computing to exist! 

If you are into computer history check the history of the data centers, the most important CPUs of all time, or learn how the computer mouse was invented.  

How does server virtualization work? 

Server virtualization works through the use of a hypervisor, which is a software or hardware layer that creates and manages virtual servers on a physical server. The process involves abstracting and sharing the underlying physical hardware resources among the virtual servers. Here are the key steps in the server virtualization process: 

1. Hypervisor installation. The server virtualization process begins with the installation of a hypervisor on the physical server. The hypervisor can be either a Type 1 (baremetal) hypervisor that runs directly on the hardware, or a Type 2 (hosted) hypervisor that runs on top of an existing operating system (OS). 

2. Hypervisor initialization. Once installed, the hypervisor initializes and takes control of the physical server’s hardware resources, including the CPU, memory, storage, and network interfaces. It becomes the intermediary layer between the hardware and the virtual servers, also known as virtual machines (VMs). 

3. Virtual servers creation. Users or administrators create virtual servers on the hypervisor. Each virtual server functions as an independent and isolated instance with its own OS, applications, and configurations. The hypervisor allocates a portion of the physical resources to each virtual server. 

4. Resource allocation. The hypervisor manages the distribution of physical resources among the virtual servers. This includes dividing CPU processing power, allocating memory, assigning storage space, and controlling network connectivity. Resource allocation is dynamic and can be adjusted based on the changing needs of the virtual servers. 

5. Virtual server operation. Virtual servers operate as if they were independent physical servers. They run their own OSs and execute applications and processes. From the perspective of the virtual server, it has dedicated access to its allocated resources, unaware of the presence of other virtual servers sharing the same physical server. 

6. Isolation. Each virtual server is independent of others, not to affect the operation of the rest. This isolation is vital to enhance security and stability. 

7. Hardware independence. Virtual servers are hardware-independent, meaning they are not tied to specific physical hardware configurations. This allows for greater flexibility, portability, and the ability to move virtual servers between different physical servers. 

8. Snapshot and cloning. The hypervisor provides features such as snapshots and cloning. Snapshots capture the current state of a virtual server, allowing for easy backup and data recovery. Cloning enables the rapid duplication of virtual servers for testing, deployment, or scaling purposes. 

9. Migration and live migration. Virtual servers can be migrated between physical servers without service interruption. This process, known as migration or live migration, allows for load balancing, hardware maintenance, and efficient resource utilization. 

10. Dynamic scaling. Server virtualization enables dynamic scaling, allowing administrators to adjust the resources allocated to virtual servers based on demand.  

Types of virtualization 

Data virtualization 

Data virtualization means that different data can be united in a single source. It lets companies use data as a dynamic resource, combining it for easy management. 

Storage virtualization 

It aggregates all storage blocks into a unified pool, facilitating their assignment to any virtual server across the network as the need arises. 

OS virtualization 

Many companies use it to provide OS for their workers and cut down hardware costs. Workers can have a basic client device and use the resources of the virtual server. This way, you can run different versions of Windows or Linux. 

Windows vs Linux for your servers?  

Desktop virtualization 

Administrators can deploy a virtual desktop environment to many physical machines at the same time. This way, they can update just one machine and share it with every client, saving a lot of time. 

Server virtualization 

Administrators can create many virtual servers from only one physical server. Each of them can run its own OS. This type of virtualization also provides redundancy. You can have two identical servers, so if one goes down, the other can still be used. 

Network virtualization 

What is virtualization in networking? Utilizing software, virtualization creates a synthesized representation of the network, so the administrator has visibility enough to manage the network from a single console. It transforms hardware elements and operations, such as connections, switches, routers, servers, cables, hubs, etc. into software entities running on a hypervisor. It allows network function virtualization. 

Network virtualization encompasses network function virtualization (NFV) to virtualize hardware appliances responsible for specific functions (traffic analyzer, firewall, or load balancer), streamlining their configuration, provisioning, and management. Software-defined networking (SDN) to virtualize the hardware controlling network traffic routing known as the “control plane”. 

Application Virtualization 

Instead of directly installing application software on the user’s OS, application virtualization allows applications to run in a virtual environment. There are three useful variations of application virtualization: server-based application virtualization, application streaming, and local application virtualization. 

Data center virtualization 

Data center virtualization extracts most of a data center’s hardware into software, allowing administrators to partition a single physical data center into multiple virtual data centers for various clients. 

CPU virtualization 

It allows a single CPU (Central Processing Unit) to be partitioned into multiple virtual CPUs for use by different virtual servers. CPU virtualization is a foundational technology supporting hypervisors, virtual servers, and OSs. 

GPU virtualization 

It empowers multiple virtual servers to utilize all or part of a single graphical processing unit’s processing power for artificial intelligence (AI), accelerated video, and other graphics- or math-intensive applications. GPU virtualization includes pass-through GPUs and shared virtual GPUs. 

Cloud virtualization 

All previous types of virtualizations converge here, making cloud computing possible and enabling providers to offer services such as infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS).  

Learn the difference between IaaS, PaaS, and SaaS.  

Linux virtualization 

Linux’s open-source nature enables high customization, facilitating the creation of virtual servers tailored for specific workloads or security-hardened versions for sensitive applications. Linux has its kernel-based virtual machine (KVM), which is its own hypervisor and supports Intel and AMD’s virtualization processor extensions. It allows the creation of x86-based VMs within a Linux host OS. 

Benefits of server virtualization 

What is virtualization server in terms of direct benefits for you? 

• Efficient resource utilization. Consolidating multiple virtual servers onto a single server allows maximum resource utilization. Organizations can achieve higher efficiency and reduce the number of underutilized servers and energy use. 
• Cost efficiency. Efficient resource utilization directly translates into considerably lower hardware and operational costs. 
• Improved flexibility and scalability. Virtual servers can be easily created, modified, or removed to adapt to changing workloads or business requirements. Organizations can scale their infrastructure up or down quickly without extensive hardware procurement and deployment. 
• Enhanced disaster recovery and business continuity. Virtual server snapshots and replicas allow organizations to create backup copies of entire virtual environments. In the event of a hardware failure or disaster, virtual servers can be quickly restored on alternative servers, minimizing downtime and ensuring the continuity of critical business operations. 
• Isolation and security. Server virtualization provides strong isolation between virtual servers. This isolation enhances security by preventing potential vulnerabilities in one virtual server from affecting others. 
• Hardware independence and simplified management. Virtual servers are hardware –independent, meaning they can run on different physical servers. This portability simplifies hardware upgrades, replacements, and migrations. Centralized management tools enable administrators to monitor, configure, and troubleshoot virtualized environments from a single interface. 

• Increased system reliability and availability. Server virtualization enhances system reliability and availability through features like load balancing and live migration. Load balancing ensures optimal distribution of workloads across available resources, preventing resource bottlenecks. Live migration allows administrators to move virtual servers between physical servers with minimal downtime, supporting hardware maintenance or upgrades without impacting ongoing operations. 

What are hypervisors? 

Hypervisors, also known as virtual machine monitors (VMMs), are software or firmware that create and manage virtual machines (VMs). 

Types of hypervisors 

Based on deployment, there are two primary types of hypervisors: Type 1 (bare metal) hypervisors and Type 2 (hosted) hypervisors. The choice between both hypervisors depends on the specific use case and requirements. 

Type 1 Hypervisor or Bare Metal Hypervisor  

It runs directly on the host’s hardware to control the hardware and manage OSs. It does not require a host OS and is considered more efficient and secure than Type 2 hypervisors. 

Use cases: Ideal for server virtualization in enterprise environments, data centers, and cloud computing. 

Examples: VMware ESXi, Microsoft Hyper-V (when installed as standalone on bare metal), Xen. 

Advantages: 

• Higher performance and efficiency. 
• Direct access to hardware resources. 
• More suitable for production environments. 

Type 2 Hypervisor or Hosted Hypervisor  

It runs on a conventional OS just like other computer programs. It requires a host OS, and VMs are created as processes within this host OS. While generally less efficient than Type 1 hypervisors, they are more user-friendly and suitable for development and testing environments. 

Use cases: Commonly used for desktop virtualization, testing, and development. 

Examples: VMware Workstation, Oracle VM VirtualBox, and Microsoft Hyper-V (when installed on top of Windows). 

Advantages: 

• Easier to set up and use. 
• Requires an existing OS, which can be an advantage for users who are more comfortable with a particular OS. 
• Suitable for non-production environments, testing, and development. 

What is virtualization in cloud computing? 

Virtualization is the technology that makes cloud computing possible. Cloud computing is a technology model that provides on-demand access to a shared pool of computing resources over the Internet. You can use the resources without buying the associated expensive infrastructure. You pay as you go. 

What is the difference between virtualization and containerization? 

Containerization is a type of application virtualization. Both technologies enable the efficient use of computing resources but through different approaches. Virtualization builds complete VMs with independent OS instances. Containerization abstracts at the application level, sharing the host OS kernel. Their use depends on the needs and use cases. They can work together, for example, in hybrid cloud environments for optimal resource utilization. 

Conclusion 

Now you know what server virtualization is! It is a foundational technology in data centers, powering the efficiency and flexibility of modern IT infrastructure. Consider your company’s needs and use it! Directly experience its numerous benefits to maximize the efficiency of your business and budget.