N+1 Power Supply Redundancy; Hot-Swappable Power Supplies; Automatic System Recovery (Asr) - Sun Microsystems Enterprise 250 Owner's Manual

details about the status and control panel LEDs, see "About the Status and Control
Panel" on page 6.

N+1 Power Supply Redundancy

The system can accommodate one or two power supplies. All system configurations
can operate with only one power supply installed. A second supply can be used to
provide N+1 redundancy, allowing the system to continue operating should one of
the power supplies fail.
For more information about power supplies, redundancy, and configuration rules,
see "About Power Supplies" on page 87.

Hot-Swappable Power Supplies

Power supplies in a redundant configuration feature a "hot-swap" capability. You
can remove and replace a faulty power supply without turning off the system power
or even shutting down the operating system. The power supplies are easily accessed
from the rear of the system, without the need to remove system covers.

Automatic System Recovery (ASR)

The system provides for automatic system recovery (ASR) from the following types
of hardware component failures:
4 CPU modules
4 Memory modules
4 PCI buses
4 System I/O interfaces
The automatic system recovery feature allows the system to resume operation after
experiencing certain hardware faults or failures. Automatic self-test features enable
the system to detect failed hardware components and an auto-configuring capability
designed into the system's boot firmware allows the system to deconfigure failed
components and restore system operation. As long as the system is capable of
operating without the failed component, the ASR features will enable the system to
reboot automatically, without operator intervention.
During the power-on sequence, if a faulty component is detected, the component is
effectively disabled and, if the system remains capable of functioning, the boot
sequence continues. In a running system, some types of failures (such as a processor
failure) will usually bring the system down. If this happens, the ASR functionality
enables the system to reboot immediately if it is possible for the system to function
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Hardware Configuration