Hot-swappable fan modules (fan trays) are provided in all switches in
the Cisco MDS 9000 Family to manage airflow and cooling for the entire switch.
Each fan module contains multiple fans to provide redundancy. The switch can
continue functioning in the following situations:
-
One or more fans fail within a fan module—Even with multiple fan
failures, switches in the Cisco MDS 9000 Family can continue functioning. When
a fan fails within a module, the functioning fans in the module increase their
speed to compensate for the failed fan(s).
-
The fan module is removed for replacement—The fan module is
designed to be removed and replaced while the system is operating without
presenting an electrical hazard or damage to the system. When replacing a
failed fan module in a running switch, be sure to replace the new fan module
within five minutes.
Note |
If one or more fans fail within a fan module, the Fan Status LED
turns red. A fan failure could lead to temperature alarms if not corrected
immediately.
|
The fan status is continuously monitored by the Cisco MDS NX-OS
software. In case of a fan failure, the following action is taken:
-
System messages are displayed.
-
Call Home alerts are sent (if configured).
-
SNMP notifications are sent (if configured).
Use the
show environment fan command to display the fan module
status.
This example shows the chassis fan information.
switch# show environment fan
------------------------------------------------------
Fan Model Hw Status
------------------------------------------------------
Chassis DS-9SLOT-FAN 1.2 ok
PS-1 -- -- ok
PS-2 -- -- absent
The possible Status field values for a fan module on the Cisco MDS 9500
Series switches are as follows:
-
If the fan module is operating properly, the status is ok.
-
If the fan is physically absent, the status is absent.
-
If the fan is physically present but not working properly, the
status is failure.
On the Cisco MDS 9513 Director, the front fan module has 15 fans. If
the front fan module (DS-13SLT-FAN-F) State field contains "failure" in the
show environment fan command output, it also displays
the numbers of the failing fans.
This example shows a Cisco MDS 9513 front fan module failure.
switch# show environment fan
------------------------------------------------------
Fan Model Hw Status
------------------------------------------------------
Chassis DS-13SLT-FAN-F 0.3 failure 3 5 6 13
Chassis DS-13SLT-FAN-R 0.3 ok
PS-1 -- -- ok
PS-2 -- -- ok
Figure 1. Cisco MDS 9513 Front Fan Module Numbering. This figure shows the numbering of the fans in the front fan module
on the Cisco MDS 9513 Director.
The rear fan module (DS-13SLT-FAN-R) on the Cisco MDS 9513 Director has
only two fans. If a fan in the rear fan module fails, the State field in the
show environment fan command output only displays
"failure" and not the failing fan number.
This example shows a fan module failure on a Cisco MDS 9513 Director.
switch# show environment fan
------------------------------------------------------
Fan Model Hw Status
------------------------------------------------------
Chassis DS-13SLT-FAN-F 0.3 ok
Chassis DS-13SLT-FAN-R 0.3 failure
PS-1 -- -- ok
PS-2 -- -- ok