Ao procurar no manual, o botão liga / desliga executa apenas um desligamento normal se o sistema operacional for compatível com ACPI.
Pela aparência da resposta aqui , você pode precisar obter o pacote acpi-support
ou, de acordo com o segunda resposta, o pacote acpid
.
Você pode experimentar qualquer um deles.
Informações de hardware diretamente do Manual do Dell Poweredge 2950:
Página 13:
NOTE: If you turn off the system using the power button and the system is running an ACPI-compliant operating system, the system performs a graceful shutdown before the power is turned off. If the system is not running an ACPI-compliant operating system, the power is turned off immediately after the power button is pressed
Página 44:
Power Button (Enabled default)
Turns system's power off and on.
• If you turn off the system using the power button and the system is running an ACPI-compliant operating system, the system can perform an orderly shutdown before power is turned off.
• If the system is not running an ACPI-compliant operating system, power is turned off immediately after the power button is pressed.
The button is enabled in the System Setup program. When disabled, the button can only turn on system power.
NOTE: You can still turn on the system by using the power button, even if the Power Button option is set to Disabled.
Fonte: ftp://ftp.dell .com / Manuais / todos os produtos / esuprt_ser_stor_net / esuprt_poweredge / poweredge-2950_owner% 27s% 20manual_en-us.pdf