The following is a sample output displaying a fan failure, along with the associated syslogs:
switch# show environment fan
Fan:
------------------------------------------------------
Fan
Model
Hw
Status
------------------------------------------------------
Fan1(sys_fan1)
N77-C7706-FAN-2
1.0
Failure(Failed Fanlets: 2 )
Fan2(sys_fan2)
N77-C7706-FAN-2
1.0
Ok
Fan3(sys_fan3)
N77-C7706-FAN-2
1.0
Ok
Fan_in_PS1
--
--
Ok
Fan_in_PS2
--
--
Ok
Fan_in_PS3
--
--
Shutdown
Fan_in_PS4
--
--
Ok
--More--2017 Mar 15 01:45:40 switch-m3100scale %$ VDC-1 %$ %PLATFORM-1-PFM_ALERT:
FAN_BAD: fan1
Fan Zone Speed %(Hex): Zone 1: 100.00(0xff)
switch#
• The fan tray is removed for replacement—The fan tray is designed to be removed and replaced while a
switch is operating, without presenting an electrical hazard or damage to the switch. Starting from Cisco
NX-OS Release 7.2(0)D1(1), use the
hardware fan-tray maintenance-mode
[
long
|
medium
|
short
]
command to put the switch in fan tray maintenance mode to prepare for fan tray removal and replacement.
For more information, see
.You have up to 72 hours to replace a fan tray as long
as the switch air-inlet temperature does not exceed 86° Fahrenheit (30° C). If the temperature exceeds
86° Fahrenheit (30° C), the switch will shut down in 3 minutes.
The switch will shut down if a mix of Gen 1 (N77-C7706-FAN) and Gen 2
(N77-C7706-FAN-2) fan trays are present in the same switch for more than 21600
seconds (6 hours). The syslog message
"PLATFORM-0-FAN_MISMATCH_TIME: Mismatch of Fan modules. Both
Gen1 and Gen2 fans are present in the fantray for <number> seconds" will be
displayed at regular intervals when both Gen 1 and Gen 2 fan trays are present
in the same switch.
Note
• If you remove more than one fan tray at a time, the switch can operate up to three minutes before shutting
down. To prevent a shutdown, remove only one fan tray at a time.
• We recommend that you do not remove more than one fan tray at a time.
• When a fan fails or when you remove a fan tray, the remaining operating
fans speed up to compensate for the loss of fans. This can increase the noise
made by the fan trays until you replace the missing fan tray or replace the
defective fan tray.
• When replacing a failed fan tray in a running system, be sure to promptly
replace the fan tray.
Note
Cisco Nexus 7706 Hardware Installation Guide
OL-31330-01
78
Managing the Switch
Overview of Fan Trays