How do I make my machine poweroff when shut down?
Power Management is a kernel function, you need to enable it in the kernel. In the 2.4 kernel, you have to enable the options for Power Management Support under General Setup. For older machines, you’ll probably want the APM options, newer machines often require ACPI. Make sure that either APM or ACPI be enabled in the kernel, but definitely not both at the same time – this has been known to cause problems such as neither actually taking effect. Also try disabling SMP if you only have one processor; it’s also known to prevent a proper poweroff. Make sure you read the help with each option. After rebooting into the new kernel you should be able to poweroff your machine with the command shutdown -h now or poweroff (also read man shutdown and man halt). If you compiled APM or ACPI as modules, make sure they are loaded before you try to power off. Some machines require that APM or ACPI is compiled into the kernel because it needs to be initialised at boottime.
