Comware

Hello,

Currently, the fan on our HP 5920 switch is running at maximum speed.  In the configuration console, it only gives me an option of changing the direction of the fan, but does not allow me to change the speed to variable.  I noticed on the datasheet, it says the switch has a variable-speed fan.  If this is the case, why is the fan always running at it's max speed?  Is there a configuration setting I overlooked?

Patel

Can't be that that FAN speed is directly related to CPU usage (more CPU usage more heat to dissipate)?

What's about checking with display cpu-usage, display cpu-usage configuration and display cpu-usage history commands?

Which software version (R24xx) your Switch is currently running?

The fan speed is related to the fan tray that is installed.  If it is running at full speed you have not set the fan direction in your configuration.

For each member of you IRF stack or individually, use the fan prefer-direction command.  For example:

fan prefer-direction slot 1 port-to-power

You can do port-to power or power-to-port, depending on which fan tray is installed.  When it is set the right way, the fans will work at the slower normal speed.

Regards,

David

It looks like the switch can become louder than I initially thought.  I switched the direction of the fan, and the switch became even louder and caused a FanDirectionFault.  I went ahead and switched it back

Here is the current state

dis fan
Slot 1
FAN 1
State : Normal
Wind Direction :Power-to-Port
Prefer Wind Direction :Power-to-Port
FAN 2
State : Normal
Wind Direction :Power-to-Port
Prefer Wind Direction :Power-to-Port

dis environment
Slot 1
System temperature information (degree centigrade):
-------------------------------------------------------------------------------
Sensor Temperature LowerLimit WarningLimit AlarmLimit ShutdownLimit
hotspot 1 43 0 62 77 NA
hotspot 2 44 0 62 77 NA
hotspot 3 43 0 62 77 NA
hotspot 4 38 0 62 77 NA

So it isn't the fan that is causing the excessive noise (compared to CISCO switches).  Is there anything else I could do to determine if I can make the switch quieter?  It is louder than the 10 servers that are being housed in the same rack.

Patel

Hi Patel!

That's surprising to me.  We have a ton of very noisy switches in our lab and it is clearly noisier when the fan direction is not set correctly.

What version of code are you running in your 5920's?

David

HP Comware Software, Version 7.1.045, Release 2311P05
Copyright (c) 2010-2014 Hewlett-Packard Development Company, L.P.
HP 5920AF-24XG Switch uptime is 7 weeks, 5 days, 19 hours, 57 minutes
Last reboot reason : Power on

Boot image: flash:/5900_5920-cmw710-boot-r2311p05.bin
Boot image version: 7.1.045P21, Release 2311P05
Compiled Dec 29 2014 16:29:56
System image: flash:/5900_5920-cmw710-system-r2311p05.bin
System image version: 7.1.045, Release 2311P05
Compiled Dec 29 2014 16:30:10

Slot 1
HP 5920AF-24XG Switch with 2 Processors
Last reboot reason : Power on
2048M bytes SDRAM
256M bytes Nor Flash Memory
Config Register points to Nor Flash

Hardware Version is Ver.C
CPLDA Version is 003, CPLDB Version is 003
BootRom Version is 132

That's pretty old compared to actual available software version (also BootROM version changed)...but...actual Release Notes don't report any particular trouble/fix related to louder Fans (note: Fan speed is automatically adjusted with regard to chassis temperature) apart from a fix introduced with R2311P02 (so a version older than the one used on your unit).