Description

A customer has reported that they frequently hear a sudden increase in fan noise.
The environment where the device was installed was well-controlled in terms of both temperature and dust. 
No temperature changes or fan speed changes were logged or found by cli. 
This article gives you an example that might trigger excessive fan noise which could not be found by cli.

Symptoms

A customer complains that they frequently hear a sudden increase in fan noise while the device is installed in a well-controlled environment. 
No logs were left suggesting a change in fan speed. 
Also, data collected by the script monitoring fan speed and temperature of various chassis components shows no evident clue for the noise experienced by the customer.

Solution

The issue was resolved after replacing a PEM module, which failed after some time the customer started complaining about the noise. 
We can collect temperatures and the exact speed of fans running in RPM by cli commands, but we cannot get the status of the fan module within a PEM. 
If everything seems to be okay based on the logs and monitoring commands, suspecting PEM may help point out the issue, as PEMs have embedded fans within, and they do not generate any monitoring data for the embedded fan.

Modification History

2023-10-16