@dalias @ariadne @leftpaddotpy @dysfun if you boot a physical system you need to wait for hw to show up, and then fsck it, mount it and so on. For that you need events for devices popping up. You cannot really build a realistic hw system without having hotplug events. It just doesn't make any sense whatsoever. Hence no, if you want systemd to to boot your system, it waits for the rootfs dev, and it waits for auxiliary devices, and it does that by watching udev, because that#s the API for that.