What is virtualization? A Deep Dive Guide

What is Virtualization?

Virtualization is a process that allows for the creation of virtual representations of physical desktops, networks, servers, storage, and other machines. It allows users to run multiple, separate and isolated environments on a single hardware system, sharing resources among multiple virtual computers. Each virtual machine runs its own operating system, acting like a completely independent computer but drawing its resources from the actual underlying computer hardware.

Virtualization enables more efficient use of a physical machine’s resources, which, in turn, ensures a better return on a business’s hardware investment. That is why it has become an industry standard for enterprise IT architecture. Furthermore, it plays a pivotal role in powering cloud computing services that helps enterprises efficiently manage IT infrastructure.

Virtual machines and Hypervisors

Hypervisors and virtual machines are two core concepts in virtualization. Now let’s talk about them in brief.

Virtual machine

A virtual machine is a software emulation of a physical machine, which runs its own separate OS and apps. The physical computer or host machine shares its resources with all the VMs or guest machines it hosts. Multiple VMs can be installed and run on a single host machine.

Hypervisor

The hypervisor, also known as the VM monitor, is a software layer that coordinates virtual machines. It serves as an interface between the virtual machine and the physical computer’s hardware and is necessary to visualize the server. This ensures that each VM has access to the host machine’s resources.

There are two types of hypervisors:

Type 1 or bare-metal hypervisors: They are installed directly on the physical machine’s hardware and manage the operating systems installed on them. Therefore, they help the VMs tap into the physical machine’s resources directly without an operating system.

Type 2 or hosted hypervisors: These are installed as a software application on an operating system, and each virtual machine runs as a separate software instance or process on the host system. Examples include VMware Workstation and Oracle VirtualBox.

How does virtualization work?

As we have seen earlier, virtualization works by abstracting the physical hardware of a computer and creating a virtual version of it. Here is a step-by-step breakdown of how it works:

Hypervisor deployment: So, to start, the hypervisor needs to be installed on the machine’s hardware (type 1) or on the existing OS (type 2).

Resource allocation: Once the hypervisor is installed, it takes control of the machine’s hardware resources.

Now, virtual machines can be created onto which an operating system is installed separately from that of the host machines. With this, all the VM’s parameters need to be defined, such as the amount of memory or CPU cores it will use.

The users can install the various apps they need on the VM’s operating system and execute them as normal. However, the hypervisor ensures that the VM can only access the resources allocated to it. If some of the apps that the user is running need additional resources, the hypervisor relays the request to the physical machine and records the changes.

Types of Virtualizations

There are many different types of virtualizations, all of which have their own advantage and purpose. Here are some of the most common types of virtualizations:

Server virtualization: With server virtualization, users can partition their physical services into smaller virtual servers to maximize server resources. This ensures that the users do not have to micromanage complicated details of server resources while increasing resource sharing, utilization, and scalability. Here, each virtual server runs its own unique operating system and apps, independent of the other virtual servers on the physical machine.

Network virtualization: Network virtualization splits the available bandwidth into independent channels that can each be assigned to specific servers or devices in real-time. This helps decrease network complexity and also improves speed, security, and flexibility by allowing multiple networks to exist on the same physical network.

Storage virtualization: This is the type of virtualization where multiple network storage resources are pooled together and appear to be a single storage device which is managed by a central console. Storage virtualization significantly helps to improve the efficiency and speed of data storage. It is commonly used in Storage area networks (SAN).

Application virtualization: This is the process of separating the application layer from the hardware and operating system. Now, the app is able to run without being dependent on the physical machine’s operating system. This way, users can run a Windows app on Linux OS and vice versa without needing to have two computers.

Desktop virtualization: With desktop virtualization, an admin can deploy simulated desktop environments on a hosted, centralized or remote server. So users can access their desktops on any workstation or device. Furthermore, it makes it easy for admins to perform updates, security checks and mass configurations on all virtual desktops.

Data virtualization: Since modern enterprises store data in multiple locations, it becomes necessary to ensure that the apps can access all that data irrespective of the location, format or source. And that is the goal of data virtualization. It involves gathering data from different sources, which can be viewed in one place, giving users a single point of access to their data.

Benefits of virtualization

Virtualization provides a plethora of benefits to any organization. Let’s take a look at some of these advantages:

Efficient resource use

In the absence of virtualization, each app server needed its own dedicated physical CPU. That is why IT staff had to purchase and configure individual servers for each app they needed to run. This was not resource efficient as the physical server was underused. However, with virtualizations, it is now possible to run several apps – each on its own virtual machine – on a single physical desktop. This way, the physical computer’s resources and capacity are efficiently used. Also, it reduces the cost of buying new hardware, frees up space in your data centre, and saves on electricity.

Easier management

By replacing physical desktops with VMs, IT admins can easily manage and use policies written in software. Creating automated IT service management workflows becomes seamless. Virtualization eliminates the cumbersome, time-consuming, and error-prone process of manually configuring and setting up physical computers or servers.

Minimal downtime

Natural disasters, cyberattacks, or OS and app crashes can cause significant downtime and disruption of user productivity with physical servers or machines. However, virtualization makes recovering from these unforeseen circumstances seamless. It ensures business continuity without lots of bottlenecks.

Why is virtualization important?

When using virtualization, users have lots of flexibility when interacting with hardware resources. Even though physical servers have their own advantages, they need maintenance, take up storage space, and consume lots of electricity. Moreover, only people who are in close proximity to these servers can access them. With virtualization, all these limitations are removed. The physical functionality of the hardware is converted to software. So this makes it possible for users to use, maintain, and manage their hardware infrastructure like an app on the web.

For example, a company has a workflow that requires them to securely store business emails and run client-side and internal business apps. All these three functions need different servers because of their difference in configuration requirements. Furthermore, the email app needs a Windows OS and better storage; the client-side app runs only on Linux and is resource-intensive; the internal business apps need lots of RAM and require iOS. For this company to have a successful workflow, they need to set up three different physical servers. This requires high upfront costs and constant maintenance and upgrades for each individual server, even though their resources will be underused.

However, with virtualization, the enterprise can create three different virtual servers for those three functions from one physical machine. Each virtual server can run its own operating system and app. Also, the resources that are needed to run each virtual server and its functions are allocated according to the physical machine. This ensures greater flexibility and scalability and, more so, fewer hardware and related expenses.

Virtualization with StarWind

When it comes to the virtualization space, StarWind has set itself up as is a one-stop virtualization shop for all the “building blocks” required to construct a full-stack data centre infrastructure.

StarWind offers software and hardware products for high-availability and data centre virtualization. For instance, StarWind Virtual SAN (vSAN) is a solution that mirrors internal hard disks and flash between hypervisor servers, eliminating the need for physical shared storage (SAN). Using this software, businesses get a fully redundant, fault-tolerant infrastructure with uninterrupted uptime.

Virtualization vs. Cloud vs. Containerization

Cloud computing is a service that delivers shared computing resources over the Internet with pay-as-you-go pricing. So, businesses don’t need to buy, own, or maintain a physical data centre. They can get their computing resources from the cloud based on their business needs.

On the other hand, cloud computing exists only because of virtualization. Virtualization helps cloud providers create and maintain their own data centres. They are able to generate multiple virtual environments that rely on the resources of the host machine’s hardware. Businesses can now access these cloud resources through APIs.

Containerization is similar to virtualization but on a much smaller scale. Instead of full machine virtualization, containerization encapsulates an app in a container with its own OS. This means that the app code is able to run on any virtual or physical environment without any tinkering. So, the developers package the app code with configuration files, related libraries, and other dependencies it needs to run.

Limitations of virtualization

Adopting a virtualized environment has a lesser upfront cost than purchasing physical equipment. However, it is still vital to consider the various upfront costs of virtualization. The necessary investments businesses need to make to ensure that virtualization is possible can still significantly weigh on the company’s budget. It becomes even more costly if the existing IT infrastructure is out of data.

Software licensing is also another bottleneck to cross when considering adopting a virtualized environment. Businesses should clearly understand the policies their vendors have when it comes to using software in the virtualized environment.

Switching to virtualization takes time, and employees need time to learn how to work in the virtualized environment. Also, not all business apps you were using in the physical environment would work well in the virtual space. So, be prepared to face those challenges and always look for alternative apps before switching.

Conclusion

Virtualization is shaping the way businesses use computer resources by enabling multiple systems and apps to run simultaneously on a single physical machine. Enterprises are benefiting from efficiency, flexibility, scalability, and cost-effectiveness in various forms like server, network, and desktop virtualization. Without any doubt, it is gradually becoming an integral part of how we manage IT resources.

Virtualization has become the building block for advancements in cloud computing and containerization. Enterprises that harness the power of virtualization can achieve enhanced IT agility and responsiveness while leading the pack in terms of innovation and growth.

This material has been prepared in collaboration with Asah Syxtus Mbuo, Technical Writer at StarWind.

 

Related materials:

• Hypervisors: Type 1 vs Type 2. [PART 1]
• Virtual Machine Storage – File vs Block [Part 1]: SMB & NFS vs iSCSI & NVMe-oF
• Virtual Machine Storage – File vs Block [Part 2]: SMB vs iSCSI vs NVMe-oF in Hyper-V

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