Onie Install
============
root@sonic:~# show reboot-cause
Unknown
root@sonic:~#

Power Cycle from Old Image(Without Fix) to New Image (with Fix)
===============================================================
root@sonic:~# show reboot-cause
Unknown

Regular Boot
============
root@sonic:/home/admin# show reboot-cause
User issued 'reboot' command [User: admin, Time: Wed Aug 28 19:47:45 UTC 2019]
root@sonic:/home/admin#
From 2.0 API
------------
REBOOT REASON :
('Non-Hardware', None)

WarmBoot
=========
root@sonic:/home/admin# show reboot-cause
User issued 'warm-reboot' command [User: admin, Time: Wed Aug 28 19:52:05 UTC 2019]
From 2.0 API
------------
REBOOT REASON :
('Non-Hardware', None)

FastBoot
========

admin@sonic:~$ sudo -s
root@sonic:/home/admin# show reboot-cause
User issued 'fast-reboot' command [User: admin, Time: Wed Aug 28 19:07:34 UTC 2019]
root@sonic:/home/admin#
From 2.0 API
------------
REBOOT REASON :
('Non-Hardware', None)

PowerCycle
==========
root@sonic:~# show reboot-cause
Power Loss
From 2.0 API
------------
REBOOT REASON :
('Power Loss', None)