Hi
One of my server(WHM/Cpanel) is getting down frequently...Changed RAM, Motherboard, chassis etc..but again same problem...no config problems....Have anyone got similar experience????

Please check whether your webserver spawns more swapping.Swapping may due to the creation of more child processes.
You can limit this by changing your Apache configuration file and limit the maximum Clients.

How secure is your box?
I would be looking at security holes. Somebody could be bringing it down

Have you installed logwatch? Try installing that and set it to send mails to you. Also try installing a port monitor like LSM, which you can download at http://rfxnetworks.com. Also manually try to check the ports,

nmap -p 1-65000 127.0.0.1

When you say 'goes down' what exactly do you mean? I am guessing if you are replacing hardware it is not just one service (e.g. Apache) going down but the whole box. Is there anything in the logs (/var/log/messages or dmesg) to indicate a hardware problem? Anything on the console (remote or local)? This is where we would start looking for clues to confirm that it is in fact a hw problem. You might want to keep two windows open on it to see what is going on. An ssh window running top and a remote or local console window for console messages. Then when it goes down you might have an idea why. No messages in the logs or console, try replacing the RAM again (with good RAM e.g. Micron/Crucial). There is a lot of bad RAM floating through the marketplace and the symptoms are usually complete crash with no error messages. Unlike a hard drive problem, when the RAM crashes the machine there frequently will be nothing in the logs or on the console. Good luck.

Try installing SIM from http://rfxnetworks.com

Your problem may due to some user or sites taking too much resources at time. SIM can monitor server load and even restart the server when load level rice to critical limit.

Old topic. Thread closed.