With the inception of virtual machines, it was viewed as a solution to the effective utilization of all server hardware.
Virtual machines have changed the fundamentals of computing and have widely shown promise in alleviating computing resource problems.
However, it is now clear the virtual machine was only a pioneer in the new computing era. Just a couple of years later and discussions about whether virtual machines are the ideal solution for creating systems in the future are already taking place.
Currently, we have a number one contender for VMs (Virtual Machines) in the software container. The container can run applications without needing an operating system (bare metal). Also, it is lighter and more portable than the Virtual Machine. This article discusses these two technologies and why your company could invest in one over the other.
What Are Virtual Machines?
First defined as ‘an isolated but efficient duplicate of the real machine’ by Popek and Goldberg, virtual machines trace their ancestry back to the 1960s where IBM engineers invented a form of virtualization for mainframes. However, the first commercial virtual machine was made available in 1972 and used a hypervisor to create and manage the VM on a machine.
A virtual machine creates an abstraction of a physical device. This includes the CPU, BIOS, disk, and network adapters. While VMs are running on dedicated servers, they also run an instance of the OS (Operating System).
In fact, VMs that are assigned to a server can run different OS versions and at times different operating systems simultaneously. The hypervisor is what will create and run the various virtual machines.
Virtual machines are useful in solving managerial problems in business in issues concerning the full utilization of machines. Creating a new VM is more straightforward than buying and installing a new physical server. The VM ensures that any hardware problem on the server is solved instantly by just moving the virtual machine to another box. Additionally, VMs offer hardware isolation which, in turn, ensures enhanced security.
Since provision times are significantly reduced, and resource utilization increased, IT departments operate more efficiently when using virtual machines. And because the VM can run different OSs, you do not need to get a second parallel server when you are upgrading.
What Are Containers?
As stated, containers came after VMs. As such, the implementation of containers has begun recently as well. However, the idea behind the container surfaced around 1979, and it was by UNIX chroot which offered UNIX operating systems isolated disk spaces for each of their processes. It wasn’t until the early 2000s when FreeBSD Jails, the earliest container technology, was introduced. The container technology progressed steadily up to 2008 when the LXC project released Linux’s first container manager.
In containers, however, it is the operating system that is virtualized instead of the physical hardware. Here, applications are run as microservices which produce the complete runtime image such as the libraries plus other utilities.
Additionally, rather than utilizing separate hypervisors to provide virtualization, a container such as Docker relies on the underlying operating system’s kernel’s functionality to inhibit applications from specific file systems and features. Thus, applications in containers share a single kernel while having separate user spaces.
Separating user spaces enables for an application to be launched together with any other third-party utility it needs for it to run. Additionally, this separation allows for the isolation of the application’s use of resources from the ongoing processes outside the container. Even though a container can run multiple applications that are related, it is typically used to produce a fine-grained level of functionality that supports various services in the system.
So, what are the main differences between virtual machines and containers?
Choosing Between Virtual Machines And Containers
You will first need to check the scope of the job. For instance, if you need to run multiple copies of the same application, you will have to take a container. If you desire is the flexibility of running multiple apps, you will need a virtual machine.
Additionally, containers tend to restrict you to a specific operating system. Even though this ensures you do not need to be concerned about dependencies once the app is up and properly running in the container, you are still limited.
Conversely, Virtual Machines allow you to run any operating system regardless of the hypervisor.
In a nutshell, if your company needs to run a maximum number of specific apps using minimum servers, then the container is for you. Nevertheless, you will need to monitor the container-running systems until its security is locked down.
If you have a variety of operating systems and require running multiple apps on servers, you will need a virtual machine. Additionally, virtual machines should remain your staple if security is a going concern in your business.
Containers have shown a vulnerability when they are used in large numbers; they can be challenging to manage. Virtual machines, on the contrary, are easier to use as they rarely reach the large quantities that containers do. Also, the sharing of a single kernel by containers poses certain risks. Theoretically, if one container compromises the kernel’s stability, it could severely affect the others.
To surmise, container and virtual machine technology are not opposing solutions. They both have their places just understand the difference . For instance, a container’s agility is futile when it comes to having multiple operating systems on the same machine. Similarly, if you have a limited capacity and resources, a container is more suitable as it is lighter than a virtual machine.