This action causes ACPI-enabled operating systems to perform an orderly shutdown of the operating system. Servers not running ACPI-enabled operating systems shut down to standby power mode immediately.
When main power is off, the Power/OK LED on the front panel begins flashing, indicating that the server is in standby power mode. See Server General Status Indicators.
Caution - When you press the Power button to enter standby power mode, power is still directed to the service processor remote management subsystem and power supply fans. To completely power off the server, you must disconnect the power cords from the back of the power supplies.