Issue description

I want to see systemd services in netdata monitoring. For that "cgroup accounting" is needed.

https://github.com/firehol/netdata/wiki/monitoring-systemd-services

The question is if enabling it on all systems would have any negative effect. In that case i would activate it only when netdata service is enabled.

Arch Linux, Ubuntu and Fedora seem to have it enabled by default. debian not.

Steps to reproduce

systemd-cgtop shows no resources for services.

Technical details

• System: NixOS 17.03.1700.51a83266d1 (Gorilla)
• Nix version: nix-env (Nix) 1.11.13
• Nixpkgs version: "17.03.1700.51a83266d1"
• Sandboxing enabled: build-use-sandbox = true