All you need to know about LXC and Docker metrics

All this stuff also applies if you don't want to use LXC, Docker, or any kind of container. You can put processes in control groups, and get all those metrics as well.

This is one of the reasons why OpenVZ was initially rejected from being included into the kernel: all the features (isolations and accounting) were mixed together, and the kernel maintainers wanted something that could be re-used in different scopes. It eventually drove the development of LXC, which is really two completely orthogonal feature sets: namespaces (to perform strict isolation) and control groups (to account and isolate resources).