SysV vs Debian Insserv vs Upstart vs Systemd: Upstart

• Mostly used on Ubuntu (also ChromeOS).

• Requires a totally different syntax (ideally better than shell).

• Does not guarantee any specific boot order.

• Very dependent on proper dependencies being found and specified by the maintainers. This is hard.

• It will deadlock and stop the boot if something is wrong, which can happen one boot out of three for instance.

• On occasion, upstart will enter states that require a reboot to clear.

• It can be hard to debug, especially on headless servers.