Unexpected power off

Support
1

I’m still learning about Nethserver, which I do like right now.
I have had 2 unexpected power off of my server in the last days. Which log file shall I look at to understand what happened?
Thank you
Loïc

2

/var/log/messages (and maybe /var/log/cron)

3

Thank you, but no interesting information in there. Maybe a “simple” power failure.