I have a redhat version 7.0 server running cgmail and dns. The server reboots on its own. It happens randomly.
I checked all the logs and did not find anything unusual.
Please let me know all the log files I need to check , just to make sure that I have not missed anything.

Also please let me if the CGMAIL or DNS is causing this.Somethimes the DNS update fails.


Thanks

You'll need to make sure that only root has priviliges to shutdown/reboot the machine. This can be done through PAM or by removing other users from the "wheel" group -depends on the version i think, but not sure-.

Next thing to note is the power supply unit for that server. Is the server very old? is the PSU fan sluggish?

Last but not least, is power stable at the location. A quick sharp drop in voltage will cause the machine to reboot though it might not be noticable otherwise. If this is the case consider getting an Uninterrupted Power Supply unit (UPS).

sounds like a hardware issue.. i'd monitor the cpu temp

Thank you for your replies.

I have requested DELL to send me an SMPS and RAM. Will swap these two and check.

this is a hardware problem, capacitors getting leaky, especially on aging motherboards and motherboards manufactured around early 2000