Both Containers and Virtual Machines are used to create isolated virtual environments for developing and testing applications or software. As Microservices have started gaining immense popularity, Containers have also, become a hot topic for developers. But how do they differ from Virtual Machines? Will Containers replace Virtual Machines? And when should you choose Containers over Virtual Machines?
This blog post throws some light on the two concepts to help you understand the difference between a Container and a VM. It defines Containers and Virtual Machines separately, as well as presents their features, to see what makes one distinct from the other.
What are Containers?
Containers is said to create isolated environments in a physical server by virtualizing the host operating system and running packaged applications on top of it. Instead of virtualizing the hardware like Virtual Machines, Containers virtualize the OS. A Container is built on top of a host OS kernel and usually shares its libraries and binaries. It consists of a master node, worker nodes and pods. A master node is the control that connects your requirements with the rest of the system, pods are where your containers are located, while worker nodes are where pods will be deployed to.
What is a Virtual Machine (VM)?
A Virtual Machine (VM) is an isolated environment that emulates a computer system with access to physical hardware resources. Virtual machines run on top of the hypervisor software, which imitates the physical infrastructure and divides the resources into multiple virtual machines. The hypervisor is also referred to as the host machine or a Virtual Machine monitor.
Containers and VMs are very similar resource virtualization technologies. However, there are some significant differences that are summarized below.
Feature – Size
- A Container can be as small as 10MB while a VM can be as large as a few gigabytes in size
Feature – Operating System
- A Container runs only the user-mode portion of the OS. You can customize containers by selecting only the services the application requires whereas, a VM runs the entire OS, including the kernel. It is resource-intensive.
Feature – Guest Compatibility
- A Container runs on the same OS version as that of the host whereas, a VM can run any OS that is inside the VM.
Feature – Networking
- Containers use an isolated view of the virtual network adapter (VNA) while, VM uses VNAs with complete virtualization.
Feature – Load Balancing
- The orchestrator starts or stops a Container on the cluster nodes automatically to handle changes in loads and availabilities. VM load balancing moves the running virtual machines to other nodes in a failed over cluster.
Feature – Fault Tolerance
- In case of a Container, if a cluster node fails, an orchestrator automatically recreates any container running on it to another node. A VM fails over to another node in the cluster rapidly, with the guest OS restarting automatically.
How to find which Solution is best for your business
VMs and containers have their own use cases. To decide which method you should use, you should look at the requirements of your application.
The container technology is rising in popularity due to its high scalability, effective resource management, and agile development cycle.
A recent study shows that the adoption of application containers will grow 30% annually by 2027.
Containers would be perfect for you if your application has a multiservice architecture, or if you want to minimize the number of servers you work on, or if your project moves through several different environment or if you’re building cloud-native applications. On the other hand, Virtual Machines are a reliable way to store your application securely and have a longer life cycle than containers.
You can also combine both virtual machines and containers to create a more suitable setup for your application. Combining VM’s flexibility and container’s efficiency also improves isolation and functionality. By implementing containers alongside VMs, you’ll be able to capitalize on the respective advantages of each.