Originally Posted by p_s_shah
Have you checked scripts in /etc/cron.daily ?
Also cross check again crontab files of all users in /var/spool/cron/.
Run a script at 16:00 which grabs output of ps -efc or ps aux into a file every minute. Check the file after server restart to find out if there is any process/script which is causing server restart.
Time difference between your server and SNMP logs may be due to different time settings on both servers. Run date command on both servers at the same time and check difference between them. If this is the cause, setup NTP for synchronized timings.
Update us your findings.
thanks for your help, I started to read, and I find there is an option on BIOS where it is a power management setting. I disable an option called ACPI, and the problem is gone. The problem was that ACPI recognice when a device as monitor, keyboard, etc is not connected then it forces the system to make a power safe and shutdown