My Ubuntu server reboots itself at random times. At first I suspected automatic updates, even though that would be strange on a fresh server install. I did make sure it was disabled.
I can find nothing in dmesg, syslog or kern.log about the cause.
What's really weird is the entries in "last reboot"
reboot system boot 4.4.0-21-generic Thu Apr 28 17:06 still running
reboot system boot 4.4.0-21-generic Mon Apr 25 20:32 still running
reboot system boot 4.4.0-21-generic Mon Apr 25 20:25 - 20:31 (00:05)
reboot system boot 4.4.0-21-generic Sat Apr 23 20:40 - 20:31 (1+23:51)
reboot system boot 4.4.0-21-generic Sat Apr 23 19:16 - 20:39 (01:23)
According to this the previous boot is still running?
Uptime says
23:10:41 up 6:04, 1 user, load average: 0,00, 0,01, 0,05
so the server did reboot.
Any ideas?