Description

When ECC errors are observed in the XQCHIP of the Flexible PIC Concentrator (FPC) and an alarm is raised by the Chassis Manager, the FPC needs to be rebooted to clear the error. This article provides more information.

Symptoms

When an "XQ-chip[0]: SCHED Core ECC errors" event occurs, messages similar to the following are reported: 

fpc5 Cmerror Op Set: XQCHIP(46): XQ-chip[0]: SCHED programmed parent for bp/nru command was null  
alarmd[4470]: Alarm set: FPC color=RED, class=CHASSIS, reason=FPC 5 Major Errors - XQ Chip Error code: 0x80002
craftd[4365]:  Major alarm set, FPC 5 Major Errors - XQ Chip Error code: 0x80002
fpc5 Cmerror Op Set: XQCHIP(46): XQ-chip[0]: SCHED Core ECC errors (status=0x400)  
fpc5 Cmerror Op Set: XQCHIP(46): XQ-chip[0]: SCHED programmed parent for bp/nru command was null

Indications

  • An FPC major alarm is raised​.

Solution

When it comes to memory errors in XQCHIP, both static and dynamic fields are part of the same software addressable memory location. So it is difficult to figure out which one caused the error.

The XQCHIP logs indicate that a memory error was detected but the corrected data is not to be written back to memory. These errors are usually transient and rare. They do not impact system behavior or functionality.

To clear the alarm, you need to reboot the FPC.

For troubleshooting purposes, however, gather the following information first:

  • 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

  • On devices running Junos OS Release 17.3 or later, the default action when a major alarm is reported is to disable the Packet Forwarding Engine (PFE), which results in the corresponding interfaces going down. Reboot the FPC to recover and clear the alarm.

  • No RMA is required.

  • Contact Support if this error is seen on multiple FPCs across the network or the issue persists even after FPC reboot.