Chassis power is provided by four hot-serviceable front-side accessible power supply units (PSUs). The four PSUs provide dual (2+2) redundancy. Therefore, the minimum PSU configuration is two. To ensure redundancy, power for the server should come from at least two separate circuits.
When the AC power cords are connected to AC inputs at the back of the chassis, the PSUs supply power to the Ethernet ports, the system sensors and inventory circuits, and the service processor (SP). When power is supplied to the SP, it boots, and the server enters the low-power standby power mode.
Once the SP boots into standby power mode, full power mode is initiated by pressing and releasing the chassis front-panel Power button or by powering on the server remotely from Oracle ILOM.
For more information about power modes, see Power Modes, Shutdowns, and Resets.