Comment 15 for bug 1824687

Knowing which was the last good kernel would be good to minimize the delta of changes. Note that if you are able to interact with the grub loader at boot, you can go back to at least the previous kernel before the reboot.
For the trace it would be good to capture the full message. If the server has IPMI capabilities you could add a console= kernel command-line to have messages observable through SOL.