I have a VPS with 512Mb RAM, 20Gb space and 100Mbps bandwidth. I'm rather new at configuring servers.. I'm using this VPS to host some websites of mine. It's running Ubuntu Server 12.04.
Every TOT hours my server becomes inusable and I need to restart it in order to take control again. I saw these errors when I restarted it: http://i.stack.imgur.com/jxGZu.png
I have apache2, php5, mysql, phpmyadmin, exim4 installed.. Could it be a RAM problem? RAM went out of memory? If I had more RAM would I solve the problem?
Here are some graphs I can see from the panel: http://i.stack.imgur.com/ydPZX.png
Can you help me? Thanks in advance. :)