Description

Chassis alarms of FANs not spinning might be seen on QFX5100-96S device. 

root@QFX5100-96s> show chassis alarms no-forwarding

3 alarms currently active
Alarm time               Class  Description
2021-01-25 10:49:15 UTC  Major  FPC 1 Fan 0 not spinning
2021-01-25 10:48:05 UTC  Major  FPC 1 Fan 2 not spinning
2021-01-25 10:48:05 UTC  Major  FPC 1 Fan 1 not spinning

 

Symptoms

Chassis alarms of FANs not spinning might be seen on QFX5100-96S device. 

root@QFX5100-96s> show chassis alarms no-forwarding

3 alarms currently active
Alarm time               Class  Description
2021-01-25 10:49:15 UTC  Major  FPC 1 Fan 0 not spinning
2021-01-25 10:48:05 UTC  Major  FPC 1 Fan 2 not spinning
2021-01-25 10:48:05 UTC  Major  FPC 1 Fan 1 not spinning

 

 

Within the syslog messages, the chassis alarms of FPC fan not spinning may appear repeatedly at major level as both alarm set and alarm cleared notifications.

 

 

Jan 25 16:09:22 2021 qfx5100-96s craftd[2101]: Major alarm set, FPC 1 Fan 0 not spinning

Jan 25 16:28:32 2021 qfx5100-96s craftd[2101]: Major alarm cleared, FPC 1 Fan 1 not spinning

Jan 25 16:28:32 2021 qfx5100-96s craftd[2101]: Major alarm cleared, FPC 1 Fan 2 not spinning

Jan 25 16:29:32 2021 qfx5100-96s craftd[2101]: Major alarm set, FPC 1 Fan 1 not spinning

Jan 25 16:29:32 2021 qfx5100-96s craftd[2101]: Major alarm set, FPC 1 Fan 2 not spinning

Jan 25 16:29:42 2021 qfx5100-96s craftd[2101]: Major alarm cleared, FPC 1 Fan 0 not spinning

Jan 25 16:30:42 2021 qfx5100-96s craftd[2101]: Major alarm set, FPC 1 Fan 0 not spinning

Jan 25 16:49:52 2021 qfx5100-96s craftd[2101]: Major alarm cleared, FPC 1 Fan 1 not spinning

Jan 25 16:49:53 2021 qfx5100-96s craftd[2101]: Major alarm cleared, FPC 1 Fan 2 not spinning

Jan 25 16:50:53 2021 qfx5100-96s craftd[2101]: Major alarm set, FPC 1 Fan 1 not spinning

Jan 25 16:50:53 2021 qfx5100-96s craftd[2101]: Major alarm set, FPC 1 Fan 2 not spinning

Jan 25 16:51:03 2021 qfx5100-96s craftd[2101]: Major alarm cleared, FPC 1 Fan 0 not spinning

Jan 25 16:52:03 2021 qfx5100-96s craftd[2101]: Major alarm set, FPC 1 Fan 0 not spinning

 

Solution

The issue arises from an incorrectly programmed fan RPM setting in the QFX5100-96S platform due to a known software defect in Juniper (PR1570587). As a result, the system generates erroneous chassis alarms and corresponding syslog messages that indicate the fans are not spinning, despite the fan functioning correctly. It is important to note that these alarms are merely cosmetic in nature and do not indicate any actual hardware malfunction.

Modification History

version 0.1 - by Peter Zhang

Related Information

https://prsearch.juniper.net/problemreport/PR1570587