In our previous article, we have explained How OS-Level Virtualization Works. As containers continue to revolutionize the way we develop and deploy applications, two popular containerization technologies have emerged as front-runners in the market: Docker and OpenVZ. While both allow for efficient resource utilization and simplified management, there are distinct differences between them that can impact their suitability for specific use cases. In this article, we’ll explore these key differences and help you understand which one might be the better choice for your organization’s needs.
Comparison of Docker and OpenVZ
Docker creates isolated environments for each application, called containers. OpenVZ creates isolated compartments which are like virtual servers, they are called “ve” or “virtual environments”.
Docker is faster and easier to use than OpenVZ. It doesn’t require a separate kernel and can run on any Linux distribution. OpenVZ requires a patched kernel and can only run on certain Linux distributions. OpenVZ is more efficient with memory and CPU usage than Docker but to run OpenVZ you need a bigger machine. With OpenVZ, multiple containers can share the same kernel, which saves memory. Docker containers are completely isolated from each other and don’t share any resources, so they’re less efficient with memory and CPU usage but Docker can run on almost any computer even on Raspberry Pi, and Android smartphones.
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OpenVZ is designed to focus on setting up VPS-like containers. You are getting templates for empty Linux machines that you can also start up and shut down, you can SSH into, and install things like LAMP stack either manually or by using some bash scripts. You are getting a virtual ethernet adapter with a publicly accessible WAN IP.
In the case of Docker, one container is a single application, to perform ONE thing. Hence, to run a LAMP stack, you need a few containers. They define the contents of a docker container (the image) by using very lightweight templates that they call Dockerfiles. If you want to run a LAMP stack in docker, you will need to run this command:
1 | docker run -d -p 80:80 tutum/lamp |
This will pull the image tutum/lamp, and will run as a demon, and the container will be forwarded to port 80 of the host. It does not have its IP address, unlike an OpenVZ instance.
Which is Better?
The advantage of Docker is that with limited resources we can create a lot of containers for upgradation, maintenance, scalability, automation etc. You can not install two instances of different versions of MySQL on one OpenVZ instance. But you can do that on Docker. You do not need to care about data in the development or staging environment. Docker is extensively used in production environments along with microservices.
OpenVZ is reliable for a production environment with limited manpower. If you are a webmaster or a small company then OpenVZ is the better option for a production environment especially for running traditional web software.
