Fan Modules

The IBM SAN96C-7 Multilayer Fabric switch supports three hot-swappable fan modules in N+1 mode. Each fan module includes two counter rotating impellers, maximizing reliability, performance and cooling efficiency. For normal operation, the switch requires two fan modules. This allows the switch to continue to operate nondisruptively if a single fan module is removed or fails, provided that the preset temperature thresholds are not exceeded.

Temperature control within the IBM SAN96C-7 switch is dependent on airflow created by the fan modules. The switch has internal temperature sensors that can shut down the system if the temperature at different points within the chassis exceeds safety thresholds. If one fan module is removed from the switch or fails, the remaining two fan modules will immediately run at full speed. If two fan modules are removed from the switch or fail, the switch will shut down after 80 seconds to prevent potential undetectable overheating. To display temperature threshold values, use the show environment temperature command.

The direction of the airflow of all fan modules installed in a switch must be the same. If all fan modules do not have the same airflow direction, then the switch is powered down after 20 seconds. Airflow direction through a fan module is denoted by a color on the module faceplate:

  • Red – indicates port-side intake airflow (DS-C96V-FAN-I).

  • Blue – indicates port-side exhaust airflow (DS-C96V-FAN-E).

To display the current status of the fan modules in the switch through the CLI, use the show inventory fan command.

Figure 1. IBM SAN96C-7 Fan Modules

The following table describes the status LED located on each fan module.

LED Status
Green Fan is operating normally
Red One or more fans in the module is faulty

The airflow direction of the PSUs must match the direction of the fan modules. If the airflow of a newly inserted power supply unit is different from that of the fan modules, the newly inserted incompatible PSU will be disabled to avoid affecting system thermal performance.

For information about replacing and installing fan modules, see Installing and Removing Components, on page 26.