Bug ID 591531: Chassis sensor errors when fan tray is not present

Last Modified: Apr 28, 2025

Affected Product(s):
BIG-IP TMOS(all modules)

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6

Opened: May 05, 2016

Severity: 3-Major

Symptoms

If the fan tray is removed from a VIPRION C2xxx-series chassis (C2400, C2200), errors similar to the following may be logged in the LTM log: err chmand[5862]: 012a0003:3: getSensorData: sensor read fault for Chassis XXXXXXXX, LOP return code 2 : File sensor/LopSensSvc.cpp Line 2315 Where 'XXXXXXXX' is the name of a Chassis sensor object.

Impact

No functional impact. These errors indicate that the Backplane Micro-Controller (BµC or 'BuC') is not responding to the periodic sensor reading requests from TMOS. In VIPRION C2xxx-series chassis, the Backplane Micro-Controller is physically located in the fan tray. When the fan tray is removed, the Backplane Micro-Controller cannot respond to these requests.

Conditions

This may occur with VIPRION C2xxx-series chassis: C2400, C2200

Workaround

Ignore errors reading Chassis sensors logged while the fan tray is not present.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips