Description

This article explains the scenario where FPC reboots due to a Data cache parity error.

Symptoms

A "Data Cache Parity Error" occurs when there is a mismatch between the parity value stored in the data cache and the parity value calculated during a parity check. This error can indicate either a hardware failure or a software issue. 
 
  1. Hardware Failure: This can happen due to data corruption in the data cache. Possible due to a faulty hardware. 
  2. Software Error: Incorrect parity information might be stored due to a software bug, leading to parity errors during data cache operations.

These errors are critical as they can affect the stability and reliability of the system, necessitating immediate attention and resolution.

 

The "Data Cache Parity Error" can be seen as the reset reason in the "show nvram" output from the affected FPC.

 

System Exception: Vector/Code 0x00200, Signal 11

Event occurred at: Sep 16 06:10:06.626325

 

Juniper Embedded Microkernel Version 18.2X43.1

Built by builder on 2021-09-24 13:34:08 UTC

Copyright (C) 1998-2021, Juniper Networks, Inc.

All rights reserved.

Reason string: "Machine Check"

Context: Thread (Idle)

Machine Check address reg 0x00000000, Syndrome 0x10000000

Data cache parity error

 

 

Solution

1. Check the NVRAM output by running the following from the FPC shell

  • Start shell pfe network fpc<>
  • show nvram

2. In the case of a single occurrence, no core is generated, and it is considered to be a transient failure. If the issue repeats, then contact JTAC for further assistance.

Modification History

2024-09-25 : Article Created