> Jails are basically like a VM-like/light […] With all due respect, they are not. The definition of a «virtual machine» is a settled matter, and the «M» in «

> Jails are basically like a VM-like/light […] With all due respect, they are not. The definition of a «virtual machine» is a settled matter, and the «M» in «VM» is important and is the differentiator: it allows one to run a different operating system kernel on the same host under the auspices of a hardware or a software supervisor (somewhat less of a defining feature). Neither jails nor cgroups possess such a property, and both restrict users to the same host operating system kernel and its version, so none of them are «VM-like/light» irregardless of the semantic interpretation of the «-like» suffix. VM-like functionality is provided by a different OS subsystem in both, Linux and FreeBSD, kernels.