Chapter 2 Controls, Ports, and Indicators
15
NOTE The power supply will continue to provide standby current to the Server until the power
cable is disconnected from the rear panel.
Multiple-Server Configurations
The HP Server temporarily draws a large "inrush current," when first connected to an AC power source. This
also occurs when the Server is in a standby mode (power is turned off and the power cord is plugged into AC
power). The inrush current is much greater than the Server's normal operating current and generally, the AC
power source can handle the normal inrush current.
However, if you install several HP Servers on one circuit, precautions are necessary. If there is a power
failure and power is then restored, all the servers immediately begin to draw inrush current at the same time.
If the circuit breakers on the incoming power line have insufficient capability, the breaker may trip and thus
prevent the servers from powering up.
When preparing your site for installation, allow for the additional inrush current. See "Power Specifications"
in Chapter 1.
Sleep States (ACPI)
The HP Server supports the ACPI (Advanced Configuration and Power Management Interface) standard,
which is a key component of a NOS's directed power management. The supported features are only available
when an ACPI-compliant NOS is installed on the Server. The term “sleep state” refers to any of several
reduced power consumption states in which normal NOS activity has ceased.
The Server supports several sleep states, including a sleep state with a short wake-up time, sometimes
referred to as “standby” or “suspend” by various operating systems. In this sleep state the Server appears to
be off, and is indicated by no display on the monitor and no activity for the CD-ROM or internal hard drives.
However, the power LED is a steady orange and the fans are operating.
The Server may also support another sleep state with a slower wake-up time, sometimes referred to as
“hibernate” by various operating systems. In this sleep state, the Server appears to be off as described earlier,
but the system fan and the front panel power LED are also turned off. The unique feature of this sleep state
(and the reason for its slower wake-up time) is that information about the Server’s NOS state (open
applications, screens, and so on) is saved to disk before the Server is placed in the sleep state. Upon wake-up,
this information is restored from disk. This method of restoring the Server's operation is much faster than a
complete rebooting of the Server. It still requires running all the start-up self-tests before starting the NOS,
but loading the NOS and all the previously opened applications is much faster.
The Server supports certain types of system activity, which are used as wake-up events from sleep states.
These wake-up events can be generated from the power button, keyboard and mouse activity, and scheduled
events.
NOTE The HP Server’s power management policies (transitions between various power states)
and the user options are specific to the particular ACPI-compliant NOS installed on the
Server. If your respective NOS is ACPI-compliant, refer to the (BIOS) Setup Utility and
the power management features described in the instructions provided for more
information.
The HP Server’s power button can be configured to initiate a graceful shutdown or "soft off" of the NOS,
rather than an immediate shutdown of the power supply. The power button configurations are dependent on
the user interface provided by the ACPI-compliant NOS. While power management is under the control of
the ACPI-compliant NOS, the HP Server’s power button is capable of an override in case of a non-responsive
NOS.
NOTE The HP Server power button will force a power down without waiting for the NOS to
gracefully shut down the Server when the power button is pressed and held in excess of
four seconds.
