Thermal Sensors; Troubleshooting - IBM 5147-084 Installation And User Manual

Thermal sensors

Thermal sensors throughout the enclosure and its components monitor the thermal health of the storage
system. Exceeding the limits of critical values will cause the Over-temperature alarm to occur.

Troubleshooting

The following sections describe problems that can occur with your storage systems and some possible
solutions. The module fault LED on the ops panel displays a solid amber color to indicate a fault. All
alarms will also be reported by SES. See Elastic Storage Server Spectrum Scale RAID Administration Guide
and the Maintenance Procedures section in Elastic Storage Server Problem Determination Guide.
Table 7. Alarm Conditions
Status
PSU alert – loss of DC power from a single PSU
Cooling module fan failure
SBB I/O module detected PSU fault
PSU removed
Enclosure configuration error (VPD)
Low temperature warning
High temperature warning
Over-temperature alarm
Under-temperature alarm
I2C bus failure
Ops panel communication error (I2C)
SBB I/O module fault
SBB I/O module removed
Drive power control fault
Drive power control fault
Insufficient power available
For information on how to remove and replace a module, see "Module Replacement."
Thermal monitoring and control
The system uses extensive thermal monitoring and takes a number of actions to ensure that component
temperatures are kept low and also to minimize acoustic noise. Air flows from the front to the rear of the
enclosure.
Symptom
If the ambient air is below 77 °F (25 °C) and the fans are observed to increase in speed, then
some restriction on airflow may be causing additional internal temperature rise.
Note: This is not a fault condition.
Cause The first stage in the thermal control process is for the fans to automatically increase in speed
when a thermal threshold is reached. This may be caused by higher ambient temperatures in the
local environment and may be perfectly normal.
Note: This threshold changes according to the number of drives and power supplies fitted.
Severity
Fault: loss of redundancy
Fault: loss of redundancy
Fault
Configuration error
Fault: critical
Warning
Warning
Fault: critical
Fault: critical
Fault: loss of redundancy
Fault: critical
Fault – critical
Warning
Warning; no loss of drive power
Fault: critical; loss of drive power
Warning
Chapter 5. Troubleshooting
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