MySQL Crashes on 512MB VPS

My VPS hosting Apache2+MySQL+Wordpress has problems with MySQL frequently. MySQL crashes and does not restart, leading to an inaccessible web site. What I initially found was the changing the Then I figured out that Apache was using 8 processes, consuming all the memory, leaving no memory for MySQL. So In apache2.conf, I changed StartServers from 5 to 2 and MaxClients from 150 to 5 to reduce the memory consumption. StartServers 2 MinSpareServers 5 MaxSpareServers 10 MaxClients 5 MaxRequestsPerChild 0