Mike Coleman

So, when do you use a Container or VM?

Recently I was giving a talk at a trade show on the basics of Docker, and how an application goes from an idea to being a production workload running on a Universal Control Plane managed Swarm cluster. As part of that talk, I spent a bit of time talking about how containers are not VMs. This was especially relevant as most of the attendees currently worked as virtualization sysadmins. During the QA portion of the session one of the attendees asked me “When does my application go in a VM and when does it go in a container?”

Mike Coleman

To Use Physical Or To Use Virtual: That is the container deployment question

I have had a version of the following conversation more than a few times with community members trying to sort out where to run their containerized apps in production: User: So, where should I run my containers? Bare metal or VM’s Me: It’s not a question of “either / or” – that’s the beauty of Docker. That choice is based solely on what’s right for your application and business goals – physical or virtual, cloud or on premise. Mix and match as your application and business needs dictate (and change). User: But, surely you have a recommendation. Me: I’m going to give you the two word answer that nobody likes: It depends. User: You’re right, I don’t like that answer. Me: I kind of figured you wouldn’t, but it really is the right answer. There are tough questions in the Continue reading…

Mike Coleman

There’s Application Virtualization and There’s Docker

In what appears to be a recurring theme (which I promise I’ll move off of soon), I’m going to spend some time talking about what Docker isn’t – Docker is not application virtualization. I spent a good amount of time at VMware where I worked on VMware View (which begat Horizon View which begat Horizon 7), so I’m more than a bit familiar with desktop and application virtualization. And, I understand why some people, when they first hear us talk about leveraging Docker for application portability they think along the lines of App-V, XenApp or ThinApp.

Mike Coleman

Containers and VMs Together

A couple weeks back I talked about how Docker containers were not virtual machines (VMs). I received a lot of positive feedback on the article (thanks!), but I also heard a common question: Can VMs and Docker containers coexist? The answer is a resounding “yes.”

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Mike Coleman

Containers are not VMs

I spend a good portion of my time at Docker talking to community members with varying degrees of familiarity with Docker and I sense a common theme: people’s natural response when first working with Docker is to try and frame it in terms of virtual machines. I can’t count the number of times I have heard Docker containers described as “lightweight VMs”. I get it because I did the exact same thing when I first started working with Docker. It’s easy to connect those dots as both technologies share some characteristics. Both are designed to provide an isolated environment in which to run an application. Additionally, in both cases that environment is represented as a binary artifact that can be moved between hosts. There may be other similarities, but to me these are the two biggies.

Mike Coleman

#SwarmWeek: Docker Swarm Exceeds Kubernetes Performance at Scale

There are people who will tell you that the community has made up its mind when it comes to container orchestration. The reality could not be further from the truth. A recent survey, of over 500 respondents, addressing questions about DevOps, microservices and the public cloud revealed a three way orchestration race between Docker Swarm, Google Kubernetes, and Amazon EC2 Container Service (ECS).