How do I find out why my UNIX server rebooted

[Snili]

Dear friends,
Last night, I realised one of my UNIX servers had re-booted itself. How can I find out the cause of this re-boot? At the time no one was even logged onto the box.

Many thanks

 

[mikeclark]

Check /var/adm/messages file and see if there are any messages before the reboot started that will help with the cause of the problem.

 

[sunguy123]

Snili,
You can check by run this command as root user:
#crontab -e
and look in there if somebody set crontab to reboot your system by itself.

Thanks,
ST

 

[nabrantes]

sunguy123,
while its possible to consult the crontab with the editor choice (-e) its way more simpler and less dangerous to check it out with the -l (list entries) option and its also more simpler because you can see all crontabs entries alot faster use it like this:

crontab -l "user"

Best Regards

Nuno Abrantes