sysvinit also has no notion of services at all. If you've got a system that's sysvinit-based, take a look in /etc/inittab sometime - that one small file is essentially everything that sysvinit knows. Setting up the system, mounting filesystems, finding and starting/stopping services, etc is all started by a handful of somewhat standardised distro-specific scripts that are run by sysvinit and hardcoded in /etc/inittab.