Nexus 5558UP-FA fan running on high speed

[operations123]

We have old Nexus 5558UP-FA switch which one running on 5.0.3 version and it was very noisy i have checked FAN speed it was. (it is not in production)

switch# sh environment fan detail

Fan:

---------------------------------------------------

Module  Fan  Airflow        Speed(%)  Speed(RPM)

             Direction

---------------------------------------------------

1       1    Front-to-Back  50        13636

1       2    Front-to-Back  50        10266

1       3    Front-to-Back  50        13775

1       4    Front-to-Back  50        10246

2       1    Front-to-Back  50        13917

2       2    Front-to-Back  50        10246

2       3    Front-to-Back  50        13881

2       4    Front-to-Back  50        10131

Power Supply:

-----------------------------------

Module  Airflow        Configured

        Direction      Speed (RPM)

-----------------------------------

1       Back-to-Front  9000

2       Front-to-Back  9000

But as soon as i upgrade to 7.0.8 version it bump the speed, what would be the issue?

switch# sh environment fan detail

Fan:

---------------------------------------------------

Module  Fan  Airflow        Speed(%)  Speed(RPM)

             Direction

---------------------------------------------------

1       1    Front-to-Back  60        15652

1       2    Front-to-Back  60        11946

1       3    Front-to-Back  60        15083

1       4    Front-to-Back  60        11637

2       1    Front-to-Back  60        15652

2       2    Front-to-Back  60        11790

2       3    Front-to-Back  60        15743

2       4    Front-to-Back  60        11894

Power Supply:

-----------------------------------

Module  Airflow        Configured

        Direction      Speed (%)

-----------------------------------

1       Front-to-Back  60

2       Unknown        60

[Kirk J]

Greetings.

Please check the output from the following:

# show logging onboard environmental-history

#show logging nvram   (look for anything environment related, temps, fans, etc)

#show processes cpu history (maybe something running in new code has the CPUs pegged)

Thanks,

Kirk...

[operations123]

Nothing interesting in output.  But after downgrade IOS fan speed get reduced. what is the operating FAN speed in idle switch? and loaded switch? 

Fan:
---------------------------------------------------
Module Fan Airflow Speed(%) Speed(RPM)
Direction
---------------------------------------------------
1 1 Front-to-Back 50 13740
1 2 Front-to-Back 50 10285
1 3 Front-to-Back 50 13810
1 4 Front-to-Back 50 10188
2 1 Front-to-Back 50 13953
2 2 Front-to-Back 50 10207
2 3 Front-to-Back 50 13846
2 4 Front-to-Back 50 10169

Power Supply:
-----------------------------------
Module Airflow Configured
Direction Speed (RPM)
-----------------------------------
1 Back-to-Front 9000
2 Front-to-Back 9000

switch# sh environment temperature

Temperature
-----------------------------------------------------------------
Module Sensor MajorThresh MinorThres CurTemp Status
(Celsius) (Celsius) (Celsius)
-----------------------------------------------------------------
1 Outlet 60 50 41 ok

[Kirk J · Accepted solution]

Greetings.

Around the 7.0.1 release there was a change to the FAN speed algorithms.

For the normal Fan speed definition what was 50 %, is now 60%, which is exactly what you are observing when running the 7.0.8 code.

Basically, this is expected behavior.

Thanks,

Kirk

[kiraciro]

hi guys i have a N5K-C5010P-BF i can't download latest fw having no license agreement.
Can any of you send it to me?

the fans remain high for me too and the electricity consumption is high despite not having connected anything.