[Trae Johnson]

Virtualization technologies are an integral part of each contemporary IT infrastructure, where efficient use of resources, flexibility in deployment, and scalability in operations are in need. Today, there are two significant types of virtualization technologies: Hardware Virtualization and Containerization. Both have certain advantages and disadvantages, which makes their application area different from one another.

Hardware Virtualization
Hardware virtualization, also commonly called full virtualization, is the creation and managing of virtual machines by an installed hypervisor. Various hypervisors, such as VMware ESXi, Microsoft Hyper-V, and Oracle VM VirtualBox, can run several operating systems on one physical machine at the same moment in time. Of course, such a feature brings much more flexibility and thus finds broad usage in data centers and cloud environments where running multiple isolated environments is needed.

The other major advantages of hardware virtualization are the isolation properties. Since each VM is running separately with an operating system of its choice, applications, and resources, the security between different environments and the isolation is very high. Hardware virtualization is ideal in scenarios where the separation between the environments needs to be secure. The support of several operating systems makes it more variant for different applications, developments, and test environments, each with a different nature. Hardware virtualization can also be further scaled through the addition of more VMs to a host machine; hence, organizations scale up their infrastructure without investing any extra in hardware. Sharma et al. 2022, et al. say that one may consider scaling the infrastructure without extra investment in hardware.

However, the downsides of hardware virtualization are serious, too. Virtual machines are resource-intensive applications requiring heavy CPU memory and large storage. Much overhead is created to which fact the reduced performance compared with running an application on the physical hardware directly contributes. Emulation of hardware components and resource management by hypervisors also add up to make this model less efficient due to the imposition of performance overhead on some high-performance computing applications, as Sharma et al. expressed in 2022. Smith and Nair expressed this idea in 2021 too. It is envisioned that, once widely deployed, multiple virtual machines add to the complexity of managing orchestration, patch management, and monitoring layers, which need to keep up in terms of both efficiency and security. Sharma et al., 2022.

Containerization
Another front-leading virtualization technology is containerization, and it occurs at the operating-system level rather than at the hardware level. Unlike hardware virtualization, which emulates physical hardware, containerization allows applications to execute in isolated user spaces hosting containers on the same operating system kernel. Technically, such containerization has been propagated as the standard way of developing, deploying, and managing applications with the use of technologies like Docker and Kubernetes.

The lightweight nature constitutes the biggest asset of containerization. Containers share the kernel of the host operating system. Because of this, it further reduces resource consumption and leads to much quicker start-up times compared with virtual machines (Merkel 2014). Because it is very much lightweight, this approach results in better resource utilization and efficiency, especially in cloud-native environments where scaling fast and deploying speedier applications is highly required. Another advantage of containerization is consistency across varied environments. Containers package an application and its dependencies into a container to reduce incompatibility problems and ensure consistency of the application from development to production. This creates room for consistency in that it will be easy to apply CI/CD pipelines, thus creating room for development agility. It is also scalable and portable; this makes it easy to move applications between diverse environments and cloud platforms with fewer changes. According to Pahl 2015, this advantage is crucial for the study.

With all these benefits, containerization brings about some challenges. This has been a big concern with containers since they would share the host OS kernel. This might be vulnerable within the kernel and may affect all running containers, which raises security risks. Containers offer less isolation than virtual machines since every container doesn’t run a separate operating system. This lower level of isolation makes them less secure for certain use cases, especially where sensitive data is handled. Networking in containerized environments can also be hard to handle, especially in hybrid or multi-cloud deployments where different network configurations and policies have to be orchestrated in an effective manner (Pahl, 2015).

Conclusion
Hardware virtualization and containerization are the two key technologies of modern IT infrastructure, each with strengths and relative weaknesses. Where high isolation is required and multiple operating systems can be run on the hardware device, hardware virtualization is used. Resource utilization, management, and overhead will have a higher cost. On the other hand, containerization enables applications to be scalable, portable, and efficient, but a container will definitely introduce shared kernel model security risks. The selection of which virtualization technology to use within an environment is quite a critical decision for any organization and needs to be given due consideration for certain use cases, security requirements, or other resource constraints.

References
Merkel, D. (2014). Docker: Lightweight Linux containers for consistent development and deployment. Linux Journal, 2014(239), 2.

Pahl, C. (2015). Containerization and the PaaS cloud. IEEE Cloud Computing, 2(3), 24-31. https://doi.org/10.1109/MCC.2015.51

Sharma, A., Sood, M., & Sabharwal, A. (2022). Virtualization technologies: An in-depth analysis. International Journal of Computer Applications, 184(14), 22-28.

Smith, J., & Nair, S. (2021). The new face of virtualization and its impact on cloud computing. Journal of Cloud Computing, 10(1), 45-60. https://doi.org/10.1186/s13677-021-00235-1