Alert Type

PSN - Product Support Notification

Product Affected

QFX5100-FAN-AFOQFX5100-FAN-AFI

Alert Description


A QFX5100 FAN failure can be falsely reported due to the fan RPM threshold being reached. This is a cosmetic alarm and is fixed via PR1093096 .

Junos may incorrectly report a FAN failure on the QFX5100 because the fan is spinning at an RPM outside of the threshold defined.
These fans are not failing and there is no need to replace them.

In the example below you will see that the "show chassis fan" output "Status" is "OK", but the "Measurement" is "Failure".
The status is OK but is falsely reporting a failure.

EXAMPLE OUTPUT: 

root> show chassis environment 
Class Item                           Status     Measurement
...
Fans  FPC 0 Fan Tray 0               Failed    
      FPC 0 Fan Tray 1               OK         Spinning at normal speed
      FPC 0 Fan Tray 2               OK         Spinning at normal speed
...


root> show chassis fan 
      Item                      Status   RPM     Measurement
      FPC 0 Tray 0 Fan 0        OK       10305   Failure                  
      FPC 0 Tray 0 Fan 1        OK       9642    Failure      
      FPC 0 Tray 1 Fan 0        OK       10424   Spinning at normal speed 
      FPC 0 Tray 1 Fan 1        OK       9557    Spinning at normal speed 
      FPC 0 Tray 2 Fan 0        OK       9523    Spinning at normal speed 
      FPC 0 Tray 2 Fan 1        OK       8723    Spinning at normal speed 
	  ...

Solution


PR1093096 fixes this problem by adjusting the RPM tolerance per specification.

Customers are encouraged to deploy a Junos release that has a fix for PR1093096.
Information on which Junos Software release that has the fix can be found below.  You can also access the (PR) problem report by using the "Problem Report Search" tool, and searching for "PR1093096".

Junos Software Release which have a fix for PR1093096:
  • 13.2X51-D38 and above Service Release       (Tentative Release Date End of June 2015)
  • 14.1X53-D27 and above Service Release       (Tentative Release Date End of June 2015)
  • 15.1R2 and above Maintenance Release       (Tentative Release Date September 2015)
  • All later releases
Please contact the Juniper Technical Assistance Center (JTAC) for additional details, or if there are questions concerning this TSB.

The fix has been committed to the releases mentioned and will be available per the tentative release dates mentioned.

Junos Software Release which have a fix for PR1093096:

  • 13.2X51-D38 and above Service Release (Tentative Release Date End of June 2015)
  • 14.1X53-D27 and above Service Release (Tentative Release Date End of June 2015)
  • 15.1R2 and above Maintenance Release (Tentative Release Date September 2015)
  • All later releases
Please contact the Juniper Technical Assistance Center (JTAC) for additional details, or if there are questions concerning this TSB.

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