HP AB500A - Integrated Lights-Out Advanced User Manual page 79

Monitoring the fan sub-system includes the sufficient, redundant, and non-redundant configurations of the
fans. Fan failure is a rare occurrence, but to ensure reliability and uptime, ProLiant servers have redundant
fan configurations. In ProLiant servers that support redundant configurations, fan or fans might fail and still
provide sufficient cooling to continue operation. iLO 2 increases fan control to continue safe operation of
the server in the event of fan failure, maintenance operations, or any event that alters cooling of the
server.
In non-redundant configurations, or redundant configurations where multiple fan failures occur, the system
might become incapable of providing the necessary cooling to protect the system from damage and to
ensure data integrity. In this condition, in addition to the cooling policies, the system might start a graceful
shutdown of the operating system and server.
The Fan tab displays the state of the replaceable fans within the server chassis. This data includes the
area cooled by each fan and the current fan speed.
Temperatures
The Temperatures tab displays the location, status, temperature, and threshold settings of temperature
sensors in the server chassis. The temperature is monitored to maintain the location temperature below the
caution threshold. If one or more sensors exceed this threshold, iLO 2 implements the recovery policy to
prevent damage to server components.
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If the temperature exceeds the caution threshold, the fan speed is increased to maximum.
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If the temperature exceeds the critical temperature, a graceful server shutdown is attempted.
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If the temperature exceeds the fatal threshold, the server is immediately turned off to prevent
permanent damage.
Monitoring policies differ depending on server requirements. Policies usually include increasing fan speed
to maximum cooling, logging the temperature event in the IML log, providing visual indication of the event
using LED indicators, and starting a graceful shutdown of the operating system to avoid data corruption.
After correcting the excessive temperature conditions additional polices are implemented including
returning the fan speed to normal, recording the event in the IML, turning off the LED indicators, and if
appropriate, canceling shutdowns in progress.
Power
The VRMs/Power Supplies tab displays the state of each VRM or power supply. VRMs are required for
each processor in the system. VRMs adjust the power to meet the needs of the processor supported. A
VRM can be replaced if it fails. A failed VRM prevents the processor from being supported.
iLO 2 also monitors power supplies in the system to ensure the longest available uptime of the server and
operating system. Power supplies can be affected by the brownouts and other electrical conditions, or AC
cords can be accidentally unplugged. These conditions result in a loss of redundancy if redundant power
supplies are configured, or result in loss of operation if redundant power supplies are not in use.
Additionally, should a power supply failure be detected (hardware failure) or the AC power cord
disconnected, appropriate events are recorded in the IML and LED indicators used.
iLO 2 monitors power supplies to ensure that they are correctly installed. This information is displayed on
the System Information page. Reviewing the System Information page and IML will assist you in deciding
when to repair or replace a power supply, preventing a disruption in service.
Using iLO 2 79