D-Series, firmware 6.03.10.0003 and lower
Fan Failure messages and traps are sent to the console, logs, and network management; for example:
Jan 5 08:00:47 172.16.21.201-1 SIM: hwutils.c(4292) 62397 %% FAN2-is NOT Functional
With this product; the fans only run occasionally, when needed for cooling under relatively extreme conditions (14554).
It is possible for the fans to have just hardware-cycled off, but the software has not yet detected it. During the period of time in which the fan status is still listed as "Ok" yet the fans are no longer spinning, the system may in error report a "FAN1-is NOT Functional" or "FAN2-is NOT Functional" condition.
Upgrade to firmware 6.03.11.0004 or higher.
If the symptoms persist after upgrade, then please contact the GTAC for assistance.
Manually determine whether or not the switch fans have failed, based on either non-operation during system boot or non-operation while the system is hot.