Fan Modules; Power Supplies - Cisco MDS 9124V-K9 Hardware Installation Manual

Overview of Cisco MDS 9124V-K9 Switch

Fan Modules

The switch fan modules have a fixed handle for insertion and removal from the chassis. The switch requires
a minimum of two operating fan modules to prevent automatic shutdown. It supports up to four fan modules.
This provides redundancy for uninterrupted operation in the event of fan module failure. The switch fan
modules are hot-swappable to also allow swapping out of a fan module during operation for uninterrupted
operation. During a fan module replacement, the internal airflow through the chassis is changed. If the internal
airflow is disrupted for too long, the preset temperature thresholds will be exceeded and the system will
automatically shut down to prevent permanent damage.
Figure 4: Fan Module
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
For more information on installing and removing fan modules, see
Units.

Power Supplies

The switch PSUs have an unswitched power socket, a PSU status LED and a handle for insertion and removal
of the PSU from the chassis. The switch requires a minimum of one operating PSU. It supports up to two
PSUs. This provides redundancy for uninterrupted operation in the event of PSU or grid failure. The PSUs
are hot-swappable to allow swapping out of a PSU during operation for uninterrupted operation. During a
PSU replacement, the internal airflow through the chassis is changed. If the internal airflow is disrupted for
too long, the preset temperature thresholds will be exceeded and the system will automatically shut down to
prevent permanent damage.
Installing and Removing Power Supply
Cisco MDS 9124V-K9 Switch Hardware Installation Guide
Fan Modules
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