Power Off the Server Gracefully (Power Button)

Press and quickly release the Power button on the front panel.

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 About Controls and Indicators and Controls and Indicators.
Disconnect the power cords and data cables from the server.

See Remove Power.

Caution:

When you power off the server using the Power button, the server enters 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 power supplies.