While upgrading HW from SCBE or SCBE2 to SCBE3, system reports unexpected behaviours like chassis process repeated crashes and chassis process core dumps.
root@labhost_re0> show version
Hostname: labhost_re0
Model: mx960
Junos: 21.2R3-S8.5
root@labhost_re0> show system processes extensive | match chassis
39627 root 41 0 865M 105M CPU2 2 0:02 15.48% chassisd{chassisd}
39627 root -26 r26 865M 105M STOP 3 0:00 3.08% chassisd{chassisd}
root@labhost_re0> show system processes extensive | match chassis |refresh 10 << chassis process not running
---(refreshed at 2024-10-31 06:46:41 UTC)---
---(refreshed at 2024-10-31 06:46:51 UTC)---
root@labhost_re0> show chassis fpc
error: the chassis-control subsystem is not running
root@labhost_re0> show chassis environment cb
root@labhost_re0> show chassis hardware
root@labhost_re0> show chassis routing-engine
root@labhost_re0> show system core-dumps
/var/crash/*core*: No such file or directory
-rw-rw---- 1 root wheel 4455209 Oct 31 05:08 /var/tmp/chassisd.core-tarball.0.tgz
-rw-rw---- 1 root wheel 4409112 Oct 31 05:08 /var/tmp/chassisd.core-tarball.1.tgz
-rw-rw---- 1 root wheel 4408727 Oct 31 05:08 /var/tmp/chassisd.core-tarball.2.tgz
-rw-rw---- 1 root wheel 4413728 Oct 31 05:08 /var/tmp/chassisd.core-tarball.3.tgz
/var/tmp/pics/*core*: No such file or directory
/var/crash/kernel.*: No such file or directory
/var/jails/rest-api/tmp/*core*: No such file or directory
/tftpboot/corefiles/*core*: No such file or directory
total files: 4
This issue usually reports in HW upgrade maintenance and is due to procedural mistakes. We noticed that, during the issue time, chassis had SCBE3 and SCBE (older generation) installed in the system. Based on the below documentation, SCBE3-MX does not interoperate with any previous generation SCBs (SCB, SCBE, and SCBE2).
https://www.juniper.net/documentation/us/en/hardware/mx960/topics/concept/scbe3-desc.html