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[diaz.cloud]

Hi there, I have two VRTX chassis and am having different results on each of them as far as fan speed goes. On one chassis the fan speed seems to always idle at around 36% even under load whereas the other unit is sitting at 58% with nothing going on.

Can't seem to find anything online on how to change this or even where to begin with this issue. Both chassis are up to date and have matching firmware. Any assistance on this matter would be extremely appreciated.

[DELL-Chris H]

https://dell.to/3X0LyZ7,

Would you confirm if the two VRTX are populated and configured identically?  My thought is that there is a difference in load, or devices installed, that are requiring a little more cooling. Another thing you can look into is if the Fan Offset is configured in the CMC.

Let me know what you see. 

[diaz.cloud]

Both chassis are configured very similarly and both have fan offset disabled. One chassis has the 10G network switch whereas the other one has the 1G network switch, outside of that they are identical. The fan speeds are different even with none of the nodes running so not sure about it being load dependent.

[DELL-Joey C]

Hi @diaz.cloud,

If the only difference between both VRTX is the switch module, is it possible to swap the switch to check the issue? Is the 10G switch, R1-2210?

[diaz.cloud]

One thing I did notice in looking through logs was the below and can't help but assume that this is the culprit as to why the chassis fans are not the same. Any idea what this issue could be?

"System was unable to read planar board or control panel temperature sensors. The fan speed was increased to protect system hardware."

[DELL-Joey C]

Hi @diaz.cloud,

This might ultimately may be caused by hardware issue, can be with the midplane, sensor cable, or the control panel sensor. But try these methods to check if this will resolve the issue. 

Try CMC reset by accessing to the CMC UI, Chassis overview > Troubleshooting tab > Reset Components > click on Reset CMC. Also you can SSH to CMC ip address run #racadm racreset CLI to reset CMC.

[diaz.cloud]

After performing the CMC reset there is no change in the chassis fan behavior.