Correct me if I'm wrong, but the sole reason why cgmanager was conceived was to have something to manage CGroups when systemd is not running. And, as Ubuntu 15.04 (vivid), is settling on systemd by default, you can just uninstall cgmanager as systemd does all the necessary CGroups management.
> Looking into cgmager for Ubuntu vivid,
Correct me if I'm wrong, but the sole reason why cgmanager was conceived was to have something to manage CGroups when systemd is not running. And, as Ubuntu 15.04 (vivid), is settling on systemd by default, you can just uninstall cgmanager as systemd does all the necessary CGroups management.
Unless there is something I am overlooking here?