Bug ID 429896: CPU fans appear to run at double speed.

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP EUD(all modules)

Known Affected Versions:

Opened: Sep 05, 2013
Severity: 5-Cosmetic


When booting a blade to the EUD application and running the 'sensor' test, then booting back to BIG-IP system, the CPU fans for that blade appear to be running at double their true speed. The fans are not actually spinning that fast. This is a reporting error only.


There is no physical impact to the CPU fans because the fans are not actually spinning that fast. The CPU fans normally spin at 6600 to 7200+ RPMs. In the error condition, the fans appear to be running anywhere from 13500 to 14400 RPMs. This is a reporting error only. Although the reporting of the fan speed appears doubled, the fans are still operating at their nominal speed of 6600 to 7200+ RPMs.


To make the error condition appear, the blade must be booted into the EUD application. In the EUD application, run the sensor validation test, option #2. After that test completes, select the option to quit and reboot the system. When the blade boots back into BIG-IP system, the CPU fans will show double the speed of the EUD sensor test.


To work around this issue, do one of the following: -- Have a serial console open to the blade running EUD and open the AOM command menu using ESC ( keystroke combination. Select to RESET the blade from that menu. -- Pull the blade from the slot and wait 10 seconds, then re-insert the blade.

Fix Information


Behavior Change