Hi,We had the same problem

ataranen · ‎03-11-2014

I encountered a problem where Nexus 5548UP is throwing the FAN_DIR_MISMATCH error on bootup and shuts itself down. The FANs are powersupplies are all matching direction. After 3-4 manual poweroffs the switch will come up properly. Below is the error and show outputs.

One suspicion I have is the fex connected to this device which uses FAN-B fans. Does Nexus 5k and its FEX have to match airflow ?

2010 Aug 31 17:06:12 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 55 seconds due to fan dir mismatch
2010 Aug 31 17:06:17 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 50 seconds due to fan dir mismatch
2010 Aug 31 17:06:22 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 45 seconds due to fan dir mismatch
2010 Aug 31 17:06:27 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 40 seconds due to fan dir mismatch
2010 Aug 31 17:06:32 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 35 seconds due to fan dir mismatch
2010 Aug 31 17:06:37 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 30 seconds due to fan dir mismatch
2010 Aug 31 17:06:42 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 25 seconds due to fan dir mismatch
2010 Aug 31 17:06:47 %$ VDC-1 %$ %PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 20 seconds due to fan dir mismatch

5k2# show module

Mod Ports Module-Type Model Status
--- ----- -------------------------------- ---------------------- ------------
1 32 O2 32X10GE/Modular Universal Pla N5K-C5548UP-SUP active *
3 0 O2 Daughter Card with L3 ASIC N55-D160L3 ok

Mod Sw Hw World-Wide-Name(s) (WWN)
--- -------------- ------ --------------------------------------------------
1 5.1(3)N2(1c) 1.0 20:01:54:7f:ee:ab:2a:40 to 20:02:54:7f:ee:ab:2a:40
3 5.1(3)N2(1c) 1.0 --

Mod MAC-Address(es) Serial-Num
--- -------------------------------------- ----------
1 547f.eeab.2a48 to 547f.eeab.2a67 FOC16227GJK
3 0000.0000.0000 to 0000.0000.000f FOC16245CA6

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

5k2# show environment

Fan:
------------------------------------------------------
Fan Model Hw Status
------------------------------------------------------
Chassis-1 N5548P-FAN -- ok
Chassis-2 N5548P-FAN -- ok
PS-1 N55-PAC-750W -- ok
PS-2 N55-PAC-750W -- ok

Temperature
-----------------------------------------------------------------
Module Sensor MajorThresh MinorThres CurTemp Status
(Celsius) (Celsius) (Celsius)
-----------------------------------------------------------------
1 Outlet 67 58 29 ok

Power Supply:
Voltage: 12 Volts
-----------------------------------------------------------
PS Model Input Power Power Status
Type (Watts) (Amp)
-----------------------------------------------------------
1 N55-PAC-750W AC 780.00 65.00 ok
2 N55-PAC-750W AC 780.00 65.00 ok

Mod Model Power Power Power Power Status
Requested Requested Allocated Allocated
(Watts) (Amp) (Watts) (Amp)
--- ---------------------- ------- ---------- --------- ---------- --------
--
1 N5K-C5548UP-SUP 492.00 41.00 492.00 41.00 powered-
up
3 N55-D160L3 144.00 12.00 144.00 12.00 powered-
up

Power Usage Summary:
--------------------
Power Supply redundancy mode: Redundant
Power Supply redundancy operational mode: Redundant

Total Power Capacity 1560.00 W

Power reserved for Supervisor(s) 492.00 W
Power currently used by Modules 144.00 W

-------------
Total Power Available 924.00 W
-------------

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

5k2# show inventory
NAME: "Chassis", DESCR: "Nexus5548 Chassis"
PID: N5K-C5548UP , VID: V01 , SN: SSI16120DP4

NAME: "Module 1", DESCR: "O2 32X10GE/Modular Universal Platform Supervisor"
PID: N5K-C5548UP , VID: V01 , SN: FOC16227GJK

NAME: "Fan 1", DESCR: "Chassis fan module"
PID: N5548P-FAN , VID: N/A , SN: N/A

NAME: "Fan 2", DESCR: "Chassis fan module"
PID: N5548P-FAN , VID: N/A , SN: N/A

NAME: "Power supply 1", DESCR: "AC power supply"
PID: N55-PAC-750W , VID: V02 , SN: POG16087T9R

NAME: "Power supply 2", DESCR: "AC power supply"
PID: N55-PAC-750W , VID: V02 , SN: POG16067T0T

NAME: "Module 3", DESCR: "O2 Daughter Card with L3 ASIC"
PID: N55-D160L3 , VID: V01 , SN: FOC16245CA6

ygazel · ‎03-11-2014

This one is interesting, however you can have the FEX with one Fan direction and the N5K with another direction, other than reseatting the PS and the FAN there should not be any issue with the parts you have now

ataranen · ‎03-15-2014

I'm still staggling with this issue. I moved fans and power supplies around. I tried running only with 1 fan and 1 PS, still this problem comes up intermittently. Do you think it could be a software issue? Can wiping out the bootflash and reinstalling help?

Javier Amores · ‎05-29-2014

Hi,

We had the same problem with a Nexus 5596 in 5.1(3)N2(1a) last night:

%NOHMS-2-NOHMS_ENV_ERR_FAN_SPEED: System minor alarm in fan tray 1: fan speed is out of range on fan 2. 5812 to 12500 rpm expected. 4072 rpm read
%NOHMS-2-NOHMS_ENV_ERR_FAN_DOWN: System minor alarm on fans: One fan missing or failed
%NOHMS-2-NOHMS_ENV_ERR_FAN_RECOVERED: Recovered: System minor alarm in fan tray 1
%NOHMS-2-NOHMS_ENV_ERR_ALL_FAN_UP: Recovered: System minor alarm on fans: One fan missing or failed
%PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 60 seconds due to fan dir mismatch
%NOHMS-2-NOHMS_ENV_ERR_FAN_DIR: System major alarm: fan direction mismatch with other fan(s)
%PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 55 seconds due to fan dir mismatch
%PFMA-0-SYS_SHUTDOWN_FAN_DIR_MISMATCH: System shutdown in 50 seconds due to fan dir mismatch

After reseating the FANs the switch came up. We'll open a TAC case.

Javier

ygazel · ‎03-17-2014

At this point I will suggest opening a TAC case since this may be related to HW itself and not something on the configuration.

HTH

Yamil

Chidojohnkingsley92 · ‎05-16-2023

https://youtu.be/qGnmCuHQSE8

Nexus 5548UP FAN_DIR_MISMATCH