Containers vs. Zones vs. Jails vs. VMs (2017)
> A “container” is just a term people use to describe a combination of Linux namespaces and cgroups. Linux namespaces and cgroups ARE first class objects. NOT containers.<p>Amen.<p>Somewhat tangential note: most developers I have met do not understand what a 'container' is. There's an aura of magic and mystique around them. And a heavy emphasis on Docker.<p>A sizable fraction will be concerned about 'container overhead' (and "scalability issues") when asked to move workloads to containers. They are usually not able to explain what the overhead would be, and what could potentially be causing it. No mention to storage, or how networking would be impacted, just CPU. That's usually said without measuring the actual performance first.<p>When I press further, what I most commonly get is the sense that they believe that containers are "like VMs, but lighter"(also, I've been told that, literally, a few times, specially when interviewing candidates). To this day, I've heard CGroups being mentioned only once.<p>I wonder if I'm stuck in the wrong bubble, or if this is widespread.