Syslog
From Linuxintro
A Linux system's syslog resides in the text file /var/log/messages.
Find a reboot
The best way to find a reboot in the syslog is to watch out for the text
syslog-ng starting up
Because usually syslog starts up after a reboot and stays up all the time. You can also watch out for
shutting down for system halt
or
shutting down for system reboot
But it happens frequently that the computer reboots because it has severe errors and these errors prevent it from writing this into /var/log/messages.
Syslog file
- For SUSE 13.1 the default syslog file is in /var/log/messages. Find out your distribution.