Cisco MDS 9132T Switch fan modules have a fixed handle for insertion into and removal from the chassis. The fan modules are hot-swappable to allow replacement of a fan module during operation for uninterrupted service. Fan blank modules must be installed in empty fan bays when operating the system for longer than several minutes to provide correct airflow and cooling. If the airflow is inadequate then the preset temperature thresholds will be exceeded and the system will automatically shut down to prevent permanent thermal damage.

The Cisco MDS 9132T Switch may be deployed with either two or four operating fan modules. One or three operating fan modules is classed as an error condition. When only two fan modules are installed there is no fan redundancy as the system requires a minimum of two operating fan modules to prevent automatic shutdown. This requirement is relaxed during fan module replacement and the system may operate for a maximum of 3 minutes with a single operating fan module for uninterrupted service. For optimal system cooling when using only two fans modules, install the modules in fan bays 2 and 4. When four fan modules are installed, there is redundancy for uninterrupted system operation in the event of up to two fan module failures.

To facilitate different data center cooling configurations of hot or cold aisles and racks, there are two models of fan modules. The first type has airflow with port-side intake and exhaust at the rear of the chassis. The second type has airflow in the opposite direction, that is, rear-chassis intake and port-side exhaust. The airflow direction is denoted on each fan module as follows:

• Red: Port-side intake airflow

• Blue: Port-side exhaust airflow

Fan Requirements for Redundancy

Note	Number of fan units is not related to the port counts that are enabled on the switch; however, we recommend that high port count configurations are deployed with fan redundancy.

• Two fan trays: No redundancy

• Four fan trays: Supports fan redundancy

The following figure shows a fan blank module:

For more information on installing and removing fan modules, see Installing and Removing Fan Modules.

The Cisco MDS 9132T Switch PSUs have an unswitched power receptacle, a PSU status LED and a handle for inserting and removing the PSU from the chassis. The Cisco MDS 9132T Switch requires a minimum of one operating power supply unit. It supports installation of up to two PSUs. This provides redundancy for uninterrupted operation in the event of PSU failure. The PSUs are hot-swappable to allow swapping out of a PSU during operation for uninterrupted operation. A PSU blank module must be installed if there is an empty PSU bay when operating for longer than several minutes to provide correct airflow. If the airflow is inadequate the preset temperature thresholds will be exceeded and the system will automatically shut down to prevent permanent damage.

The switch supports any one of the following PSUs:

• 650-W AC, port-side exhaust variant (up to two per switch)

• 650-W AC, port-side intake variant (up to two per switch)

The switch supports PSUs of only one airflow type at a time. Both PSUs have to be either port-side exhaust, or port-side intake PSUs.

To facilitate different data center cooling configurations of hot or cold aisles and racks, there are two models of PSUs. The first type has airflow with port-side intake and exhaust at the rear of the chassis. The second type has airflow in the opposite direction, that is, rear chassis intake and port-side exhaust. The airflow direction is denoted on each PSU as follows:

• Red—Port-side intake airflow

• Blue—Port-side exhaust airflow

Note	The direction of PSU airflow must match the direction of the fan module airflow.

Power Suppply Requirements for Redundancy

Note	Number of power supply units is not related to the port counts that are enabled on the switch; however, we recommend that high port count configurations are deployed with power supply redundancy.

• One power supply: No redundancy

• Two power supplies: 1:1 power redundancy

The following figure shows a power supply blank module:

For more information on installing and removing PSUs, see Installing and Removing Power Supplies.

The Linecard Expansion Module (LEM) is a pluggable expansion module for the Cisco MDS 9132T Switch.

The LEM is field replaceable in the Cisco MDS 9132T Switch. However, this module is not hot swappable; the switch must be powered down before removing or inserting it.

The LEM blank module must be installed if the LEM bay is empty when operating for longer than several minutes to provide correct airflow. If the airflow is inadequate the preset temperature thresholds will be exceeded and the system will automatically shut down to prevent permanent damage.

For more information on installing and removing the LEM, see the chapter "Installing the Cisco MDS 9132T Fibre Channel Switch."

SFP+ transceivers are field-replaceable. You can use any combination of SFP+ transceivers that are supported by the switch. The only restrictions are that Shortwave (SW) transceivers must be paired with SW transceivers on the peer device, and Longwave (LW) transceivers with LW transceivers on the peer device, and the cable must not exceed the stipulated cable length for reliable communications.

For a list of SFP+ transceivers supported on the Cisco MDS 9132T Switch, see SFP Transceiver Specifications. SFP+ transceivers can be ordered either separately or with the Cisco MDS 9132T Switch.

Note	Use only Cisco SFP+ transceivers in the Cisco MDS 9132T switches. Each Cisco SFP+ transceiver is encoded with model information that enables the switch to verify that the SFP+ transceiver meets the requirements for the switch.