virtualization

Addressing Time Drift in Docker Desktop for Mac

Docker Desktop for Mac runs the Docker engine and Linux containers in a helper LinuxKit VM since macOS doesn’t have native container support. The helper VM has its own internal clock, separate from the host’s clock. When the two clocks drift apart then suddenly...

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...

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...

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.” At...

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...