Symptom
RSP repeatedly reloading with below messages on the console.
Nov 22 08:20:05 diskmon start/running, process 4415
Nov 22 08:20:06 initctl: Unknown instance: /dev/ttyS0
Nov 22 08:20:06
Nov 22 08:26:05 calvados bootup timer expired
Nov 22 08:26:06 Notify admin vm failure to standby
Nov 22 08:32:13 calvados bootup timer expired
Nov 22 08:32:13 Notify admin vm failure to standby
Nov 22 08:33:07
Boot Region: Upgrade
Nov 22 08:33:08
Nov 22 0 :33:08 PK 791
Conditions
This issue could be seen while RSPs are booting up post system power cycle or while RSP is booting up post HW reload from sysadmin.
Workaround
Based on internal recovery tests, Reimage (PXE boot) of chassis helped recover the RSP.
Please refer "Boot the Router Using iPXE" section of below doc for pxeboot steps.
https://www.cisco.com/c/en/us/td/docs/iosxr/ncs560/system-setup/66x/b-system-setup-cg-66x-ncs560/cg_65_perform_disaster_recovery.html
Issue is extremely rarely seen so other workable workarounds are not known.
Further Problem Description
