Docker vs Virtual machine

What is Docker?

An application can be developed, deployed, monitored, and executed within a Docker Container including all of its components thanks to the widely used virtualized environment known as Docker.

All components (frameworks, libraries, etc.) needed to operate software effectively and error-free are included in Docker containers.

What is a Virtual Machine?

The Virtual Machine is a platform that mimics the behavior of a computer. It's a program or computing framework that allows developers to use an OS from a physical server.

To put it simply, it allows you to operate what looks to be several computers on a single computer's equipment. The base operating system for each Virtual Machine is required, and then the hardware is digitized.

Difference between Docker & VI

Security

The Virtual Machine doesn't quite share its OS, and the hosting kernel is highly isolated. As a result, these are safer than Containers. Because containers use a common host kernel, they provide several security threats and weaknesses.

Furthermore, because Docker assets are pooled and not namespaced, an intruder who gains entry to even a single container in a group can exploit the entire cluster. You will not have unfettered accessibility to assets in a Virtual Machine, and the hypervisor would be there to control how those resources are used.

Operating System Support

The supporting OS of both, Docker and Virtual Machines, is significantly different. Each Virtual Machine's guest OS runs on top of the host system, making virtual computers bulky. 

Docker containers, however, use a shared host operating system, hence the reason they are light.  This allows the containers to boot up in a matter of seconds. As a result, when contrasted with Virtual Machines, the expense of managing the container system is quite minimal.

Portability

Docker containers are lightweight and portable due to the lack of a distinct operating system. A container could be transferred to a different operating system and run right away. 

Virtual Machines, however, have their operating system, making porting them more challenging than porting containers. It also requires a long while to transfer a Virtual Machine due to its scale.

Docker containers are useful for developmental reasons when applications must be built and tested across multiple platforms.

Speed

Because the OS is already fully operational, the software in Docker containers begins immediately. These containers were created to conserve time during the software deployment process.

On the other hand, it takes far longer for a container to launch apps on a Virtual Machine than it does for a container. Virtual Machines must launch the complete OS to launch a single program, resulting in a full boot procedure.

Performance

It would be unfair to compare Virtual Machines to Docker Containers since they are utilized for distinct reasons. However, Docker's lightweight design and resource-saving functionality make it a better solution as compared to a Virtual Machine. As a consequence, containers can boot up much faster than Virtual Machines, and resource utilization changes based on the strain or activity in the container.

Containers, contrary to Virtual Machines, do not require a persistent allocation of resources. In comparison to Virtual Machines, expanding and replicating containers is also simple because they do not require the installation of an operating system.

Docker Architecture

The Docker Client, Docker Host, and Docker Registry are the three primary components of Docker which follows Client-Server architecture. Let us try to understand each one of these components one by one.

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Docker Client

The Docker client communicates with the Docker Daemon using commands and REST APIs (Server). Whenever a client uses the Docker client terminal to execute a Docker command, the client terminal delivers the command to the Docker daemon. The Docker daemon gets these commands in the type of command and REST API requests from the Docker client.

Popular commands used by clients are:

Docker build
Docker pull
Docker run

Docker Host is often used to offer an environment in which programs can be executed. The Docker daemon, images, containers, networks, and storage are all included in Docker Host.

Docker Registry is a service that takes care of the management and storage of Docker images. There are two types of registry- private and public registry.

Virtual Machine Architecture

The Virtual Machine contains anything that is needed to execute a program, including virtualized hardware, an operating system, and any required binary or library. As a result, Virtual Machines are self-contained and have their architecture.

The host operating system is totally segregated from each VM. It also needs its operating system, which may vary from the host's. Each one has its own set of binaries, libraries, and apps.

Advantages of Docker

Higher ROI

The first benefit of Dockers is the return on investment. It can bring down expenses while increasing profits, particularly for big, established organizations that need to create consistent profit in the long run.

Configurations are faster and easier

One of Docker's main advantages is how it simplifies things. Users may easily take their existing configuration, turn it into code, and deploy it. Because Docker may be utilized in a wide range of contexts, the infrastructure needs are no longer tied to the application's environment.

Quick Deployment

Docker can decrease deployment time to a matter of seconds. This is because it generates a container for each process and does not boot an operating system. You can create or destroy data without fear of the expense of bringing it back up being too costly to justify.

Security

By giving us total power over traffic conditions and administration, Docker ensures that software running in containers is entirely separated and isolated from one another from a security standpoint.

Disadvantages of Docker

Under progress features

A large number of feature requirements are currently being worked on, including container self-registration and self-inspections, file transfer from the host to the container, and many others.

Missing documentation

Docker is evolving at a breakneck speed, making it difficult to follow the latest developments and updates. While the documentation is excellent, there appear to be some loopholes, particularly in the description of the abstraction layers

Learning curve

It takes a long time to learn Docker. Even for skilled developers, many principles are just distinct enough from a Virtual Machine architecture to create possible misunderstandings making unlearning principles from other domains a bit tougher.

Advantages of Virtual Machine

Hardware expenses are reduced

Many businesses do not make complete use of their hardware resources. Rather than investing in a new server, businesses can create virtual servers.

Data security is strengthened

Once you replicate the servers in the cloud, virtualization simplifies disaster recovery. Businesses don't require the same dedicated server offsite for a backup recovery site because Virtual Machines are independent of the actual hardware.

Faster desktop provisioning and deployment

Many time-consuming tasks go into deploying a new physical server. Businesses may swiftly deploy new virtual servers utilizing safe pre-configured server templates with Virtual Machines.

The footprint is reduced

Virtualization frees up extra space to support additional employees while also reducing the amount of office space necessary to manage and grow IT skills.

Portability

With minimum interaction from IT professionals, VMs may be moved effortlessly between virtual environments and even from one physical server to the other. Virtual Machines (VMs) are hardware-independent since they are separated from each other and use their virtual hardware. It takes more resources to move physical servers to some other place.

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Disadvantages of Virtual Machine

Performance

Virtual Machines use the host machine's resources. To execute multiple Virtual Machines on a single host computer, a computer must be strong enough. If its power is insufficient, it will lead to performance instability.

Efficiency

A Virtual Machine is much less efficient when it comes to hardware connectivity. It is unable to gain direct access to the hardware. Furthermore, for most IT organizations, its speed is insufficient. As a result, they employ a system that is both virtual and physical in nature.

Infections

While a well-structured VM cannot infect a host, a faulty host system can have an influence on its Virtual Machines. This frequently occurs whenever the operating system contains bugs. Infections may transmit to other Virtual Machines if 2 or more Virtual Machines are attached to one another.

Complicated

A Virtual Machine is a complicated piece of software. Its complexity stems from the fact that it is outfitted with numerous local area networks. As a result, in the event of a failure, pinpointing the source of the problem will be challenging. Particularly for those who are acquainted with the Virtual Machine's architecture and hardware.

Docker Vs VM Which is a Better Choice?

Comparing Docker with Virtual Machines isn't appropriate because they're designed for distinct purposes. Docker is gaining popularity these days, yet it cannot be argued that it can substitute Virtual Machines. Despite Docker's growing popularity, in some circumstances, a VM is a superior option. Virtual Machines are preferred in a production setting, instead of Docker containers, since they operate on their OS and do not present a risk to the host machine. However, if the apps need to be evaluated, Docker is the way to go, since it offers a variety of OS platforms for extensive testing of software or applications.

Furthermore, because the deployment is somewhat prolonged and running microservices is among the biggest issues, not that many virtual operational firms count on VMs as their leading solution and want to migrate to containers.  Nevertheless, some businesses still favor Virtual Machines with Dockers, whilst businesses seeking enterprise-level protection for their infrastructure choose Dockers. 

Lastly, Docker is not a competitor to Virtual Machines; rather, they are complementing solutions for diverse workloads and applications. Virtual Machines are designed for apps that are typically static and seldom modified. The Docker platform, on the other hand, is designed to be more versatile, allowing containers to be upgraded rapidly and effortlessly.

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Conclusion 

VMs and Docker both have advantages and disadvantages. Each workload in a VM environment requires its own operating system. However, in a container environment, several workloads can run on a single operating system. Containers improve the environment more when the OS footprint grows. It also has other advantages, such as decreased IT management resources, smaller snapshots, faster app spin-up, lower and easier security upgrades, and far less coding for transferring, migrating, and uploading workloads.

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