Description

The "Parity error for free pointer SRAM" message reports memory parity error in the XMCHIP.

This is a Troubleshooting Article for a PFE ASIC Syslog Event.
To view other documented syslog events related to XMCHIP, XLCHIP, MQCHIP, LUCHIP, EACHIP, and PECHIP, see KB31893 - Master Index of Articles for Troubleshooting PFE ASIC Syslog Events [juniper.net] .

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Symptoms

When a "Parity error for free pointer SRAM" event occurs, a message similar to the following is reported:

Aug 21 16:35:36.765 2017 router-0 fpc9 XMCHIP(0):XMCHIP(0): DDRIF: LLISTQ Protect: Parity error for free pointer SRAM (0x1)
Aug 21 16:35:37.330 2017 router-0 alarmd[2266]: Alarm set: FPC color=RED, class=CHASSIS, reason=FPC 9 Major Errors
Aug 21 16:35:37.330 2017 router-0 craftd[1626]: Major alarm set, FPC 9 Major Errors
Aug 21 16:35:42.324 2017 router-0 fpc9 XMCHIP(0):XMCHIP(0): DDRIF: LLISTQ Protect: Multiple Errors 0x0

Indications:

 

Solution

This is due to a transient memory hardware error on the XMCHIP. If there is a service impact, then other events will be reported.

Perform these steps to determine the cause and resolve the problem (if any).  Continue through each step until the problem is resolved.

  1. Collect the show command output.

    Capture the output to a file (in case you have to open a technical support case). To do this, configure each SSH client/terminal emulator to log your session.

    show log messages
    show log chassisd
    start shell network pfe <fpc#>
    show nvram
    show syslog messages
    exit

  2. Analyze the show command output.

    In the 'show log messages', review the events that occurred at or just before the appearance of the "Parity error for free pointer SRAM"" message. Frequently these events help identify the cause.

  • No RMA is required with a single occurrence

  • With a single occurrence, the alarm can be cleared using the following command:

    • clear chassis fpc errors fpc-slot  <x> all

    • Note:  This command is available in Junos OS 16.1R4-S2, 16.1R5, 16.2R2, 17.1R2, and 17.2R1 or higher.

      According to the technical documentation on  clear chassis fpc errors , this command is supported on Junos starting from 18.2R1.

  • Contact your technical support representative if this issue is seen repeatedly or together with other events.

This article is indexed in  KB31893 - Primary Index of Articles for Troubleshooting PFE ASIC Syslog Events [juniper.net] ; tag XMCHIPTSG

Tip: When looking at an event in the logs, it is important to focus on the first error message in a collection of syslog messages. The first error message is usually the cause of all the follow-on error messages. The follow-on collateral damage error messages can be ignored.

 

Modification History

2019-10-14: Article reviewed for accuracy; no changes required.