Fan Properties

The operation of various system components generates heat. Maintaining an appropriate operating temperature inside the system chassis is therefore critical. Fans are one component that help with temperature control.

Some fan probes monitor fan status by measuring fan RPM. Other fan probes report an ON or OFF status for a particular fan. Fan probes report the RPM or ON/OFF status to the Server Administrator instrumentation service. When you select Fans from the device tree, details appear in the data area on the right-hand side of the Server Administrator window.

Fan User Privileges

System Tree Selection  Tab Subtab User Privileges
    View Manage
Main System Chassis
Fans Properties Fan Probes U, P, A P, A

U=User; P=Power User; A=Administrator; NA=Not Applicable. For more details on user privilege levels, see "Privilege Levels in the Server Administrator GUI."

Fan Redundancy 

Systems can be designed with redundant fans to prevent system shutdown due to fan failure. When fans are present in a system, being able to see that one or two fans have failed enables administrators to replace fans and restore redundancy before the last fan failure causes the entire system to fail. 

Redundancy Status Status can be Full, Degraded, or Lost. If the number of fans in a system that is required for full redundancy is three, then:
  • Redundancy status is Full when three fans are working.
  • Redundancy status is Degraded when two fans are working.
  • Redundancy status is Lost when one fan is working.

Full redundancy is defined by system specification. Degraded redundancy means that one or more of the extra fans is not working in the normal range. Lost redundancy means that there are no backup fans available to take over for the minimum number required, but at least one fan is working. 

Critical/Failure status would describe a system that had no working fan, and redundancy is designed to make this sort of system failure unlikely.

Number of Devices  Required for Full Redundancy Your system has a number of fans defined for full redundancy. If the number of fans required for Full redundancy is three, redundancy is degraded when two fans are working, and lost when only one fan is working.

Fan Status Information

Critical components have an event type associated with them at all times. Status is a shorthand term for the component's event type. Status can be given for a component's operational state as well as for its redundancy state, if applicable. See "Event Type Definitions and Component Health" for more information on status and related concepts.

Some fan probes monitor fan status by measuring fan RPM. Other fan probes report an ON or OFF status for a particular fan. When you select Fans from the device tree, details appear in the data area in the right-hand side of the Server Administrator window. Fan status is one of the following states:

OK
Noncritical
Critical/Failure
Unknown (Blank)

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Fan Probe Fields

Status Displays whether the event type for the probe is Normal, Warning, or Failure.
Probe Name The alphanumeric text that uniquely identifies a fan probe; for example, CPU Fan
Reading Snapshot of a fan RPM actually measured by the probe at a given time.
Minimum Warning Threshold The lowest acceptable fan RPM that is recommended for system operation. Values that fall below this RPM level result in warning events.
Maximum Warning Threshold The highest acceptable fan RPM that is recommended for system operation. Values that exceed this fan RPM result in warning events.
Minimum Failure Threshold The lowest acceptable fan RPM that is required for system operation. Values that fall below this fan RPM result in critical/failure events.
Maximum Failure Threshold The highest acceptable fan RPM that is required for system operation. Values that exceed this fan RPM result in critical/failure events.

Managing Fan Probes

For information on how to set warning thresholds for fan probes, see "Edit Fan Probes."

For information on how to set alert actions for fan probes, see "Set Alert Actions."

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