Virtual Machines and Containers – Similarities and Differences

There’s a universal increase in IT expenses. Presently, organizations are spending billions on their software alone. These companies are searching for a technology that can reduce their IT expenses. Containerization is a modern technology that has presented itself to be a solution to the rising IT cost. Containerization entails the use of standardized containers, similar to the physical containers that shipping companies use. Developers use the same blueprint to create application containers. This implies that an application is developed with several dependencies, runtime components, and other aspects that are segregated from other vital processes.

Prior to the inception of containers, organizations used virtual machine technology to optimize their server capacity. Virtual Machines were programmed to imitate the hardware of a physical computer with the usual operating system. Hence, virtualization made it possible to operate multiple computers utilizing unique operating systems located on a single physical server when coupled with hypervisors.

Generally, virtual machines require a huge amount of system resources and are heavyweight compared to containers. Due to the lightweight features of containers have become suitable for working in diverse environmental conditions such as network security, secure socket layers, and operating systems. Environmental differences are among the mundane factors contributing to incompatibility system crashes. For this reason, many famous companies, including Google and Amazon, have adopted the container software strategy.

What is Containerization?

A container is a segregated unit of software that runs on an operating system, most commonly Windows OS or Linux OS. A container doesn’t operate the entire system; rather, it runs only applications and their dependencies. Interestingly, containers are not required to operate on an entire operating system. Instead, containers distribute the operating system kernels and obtain access to hardware via the functionality of the host operating system. As a result, containers are more compact, faster, and more efficient.

Containerization is the use of this container technology. Containers enable developers to boost CPU and memory utilization on hardware machines. As its name implies, container technology earned its name from the common shipping industry. The idea behind it is very logical. Instead of shipping products the usual way, place each product in containers that have been designated for pickup by cranes on the dock. When they’re picked up, each container should be placed on ships that can accommodate the container’s standard size. This is more like a standardized strategy.

Containerization is simply the use of containers to package an application so it can operate with its dependencies, separated from other operations. Most famous cloud computing providers, such as Amazon, Microsoft Azure, and Google Cloud, have adopted container technology. This container software has been assigned different names, such as Docker, Kubernetes, etc.

What is Virtualization?

TechTarget defines virtualization as the method of creating a virtual rendition of certain systems rather than their physical versions. Virtual versions of a server, storage device, operating system, or network resources can be created. Virtualization utilizes software that replicates hardware functionality to develop a virtual system. Virtual machines enable IT organizations to operate several operating systems, virtual systems, and numerous applications on a single server. This provides an organization with greater efficiency and better management.

When operating systems are virtualized, the software is used to bolster hardware so that this hardware can run multiple operating systems simultaneously. The concept of virtualization originated from the mainframes years ago. And since virtualization helps administrators to save processing power, it has been widely adopted.

Virtualization creates the virtual rendition of a computer system in a layer abstracted from the original hardware. Usually, applications operating on virtualized machines can appear as if they are on their own designated machine. Their operating systems and extra programs are specific to the guest virtualized system and unlinked to the host operating system that resides below it.

There are several reasons organizations use virtualization in their computing process. Basically, desktop users employ virtual machines to run applications that are intended for different operating systems without having to transit between servers or load them into a different system. Also, virtualization allows administrators to manage different operating systems such that large segments are divided into compartments, allowing the server to function more effectively when used by several with different needs. Furthermore, virtualization enables segregation, shielding programs within a virtual machine from other processes in another virtual machine on the same host.

Containerization vs. Virtualization

Containerization and virtualization are among the basic and core mechanisms used by host applications in a computer system. Virtualization, on its end, utilizes the concept of virtual machines. While containerization employs the concept of a container. These two technologies play a vital role, have similarities and unique features, and have several advantages and disadvantages.

Generally, virtualization enables users to operate several operating systems on a particular hardware server, while containerization provides users with the ability to deploy several applications using a specific operating system on a single virtual machine or server. When it comes to bolstering applications that demand an operating system’s complete functionality when users want to utilize numerous applications on a server or when they’re tasked with managing multiple applications.

Users’ needs are a major determinant too. Burwood asserts containers are the best option for tasks that have a shorter life cycle. Containers have a quick setup time that makes them suitable for tasks that require a few hours. On the other hand, virtual machines possess a longer life cycle than containers and are appropriate for tasks that require longer periods. Hence, the method adopted by an organization will rely upon several factors, including the extent of the operation, organizational workflow, IT standards, and skill set.

When all these are considered, containerization and virtualization technologies come in several ways that can influence an organization’s decision-making. Eventually, virtualization and containerization may both be suitable for an organization’s IT strategy.

Aspect Containerization Virtualization
Operating Systems

Containerization functions on the user-mode aspect of an operating system and can be crafted to contain only the required services for an application, consuming fewer system resources. 

Virtualization functions on a complete operating system including kernel. Therefore, it requires additional system resources such as CPU, memory, and storage. 

Isolation

Serves as lightweight isolation from the host and other containers. However, its characteristic security boundary is lesser than that of virtualization.

Provides absolute isolation from the host’s operating system and other virtual machines. 

Deployment

This technology deploys individual containers by using Docker. It can also deploy multiple containers via an orchestrator such as Kubernetes.

Virtualization deploys each virtual machine by using hypervisor software 

Persistent Storage

Containerization utilizes local disks for an individual node or Server Message Block(SMB) for storage shared among multiple servers.

Virtualization employs virtual hard disks for local storage for each virtual machine or Server Message Block file shared among multiple servers. 

Load Balancing

Containerization uses orchestrators that can automatically initiate or terminate containers on cluster nodes to handle changes in load and availability. 

Virtualization performs load balancing by operating virtual machines in other servers in a failover cluster. 

Guest Compatibility

Functions on a similar operating system version as the host.

Functions on almost any operating system that resides in the virtual machine.

 

 

Containerization Pros and Cons

Every day, developers are searching for new methods of applying containerization to solve their challenges. There’s almost no limit when it comes to using containerization, and every application will deliver unique benefits.

Containerization Pros

  • Efficiency

Containerization has proven to be among the most efficient IT methods available to developers. Containers boost efficiency in some ways; by minimizing overhead and by a complete utilization of available resources. When properly programmed containers, they allow a host to enjoy the benefits of all available resources. Since an isolated container can carry out its operations without hindering other containers, a single host can carry out multiple functions.

  • Security

By isolating individual containers, containerization provides users with an extra layer of security. This is because when containers are isolated from one another, users can rest assured that their applications are running in their unique self-contained environment. This implies that even if there’s a security breach in one of the containers, other containers on the same host remain intact.

Containerization Cons

  • Sprawling

It is well established that virtual machine lifecycle management is crucial for hypervisor-based environments. Lifecycle management is even more important for containers. Containers can be spun and duplicated at an astounding rate. Even though this might appear to be an essential benefit for containers, it might cause the consumption of a vast amount of computing resources.

  • Inadequate Tools

TechTarget affirms that the type of tools suitable for properly monitoring and maintaining containers is still lacking, or better still, inadequate. These entail Google open source Docker management tools, Kubernetes, DockerUI to substitute Linux command line functions with a cloud front end, etc.

One thing we can all agree on is that containers are a legacy virtualization technology that has earned an immense amount of interest. Learn more about containerization:

Marcin Kubacki

text written by:

Marcin Kubacki, CSA at Storware