System Board Management Controller (Bmc) - NEC EXPRESS 5800 User Manual

1-22 System Overview

System Board Management Controller (BMC)

Server management is concentrated in the System Board Management Controller (BMC). The
BMC and associated circuitry are powered from a 5Vdc standby voltage, which remains active
when system power is switched off, but the ac power source is still on and connected.
The BMC supports the Management Workstation Application (MWA), which allows remote
server management via a LAN, a modem, or direct connection to a manager system. Events
monitored by the manager system include over-temperature and over-voltage conditions, fan
failure, or chassis intrusion.
Information on the MWA may be found in the ESMPRO User's guide on the ESMPRO CD-ROM
included with your server.
One major function of the BMC is to autonomously monitor system management events, and log
their occurrence in the nonvolatile System Event Log (SEL). The events being monitored include
overtemperature and overvoltage conditions, fan failure, or chassis intrusion. To enable accurate
monitoring, the BMC maintains the nonvolatile Sensor Data Record (SDR), from which sensor
information can be retrieved. The BMC provides an ISA host interface to SDR sensor
information, so that software running on the server can poll and retrieve the server's current
status.
The BMC performs the following:
Monitors server board temperature and voltage
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Monitors processor presence and controls Fault Resilient Boot (FRB)
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Detects and indicates baseboard fan failure
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Manages the SEL interface
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Manages the SDR Repository interface
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Monitors the SDR/SEL timestamp clock
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Monitors the system management watchdog timer
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Monitors the periodic SMI timer
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Monitors the event receiver
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Controls secure mode, including video blanking, diskette write-protect monitoring, and
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front panel lock/unlock initiation
Controls Wake On LAN via Magic Packet support.
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