I recently updated from 7.0.25. I was able to start with -Xmx32m. After getting 7.0.27 - I ended up needing to go all the way to -Xmx512m. Note that the OOM only occured on startup. After starting up and attaching with JConsole - Heap was very small.
I was able to get 7.0.27 back to to -Xmx32m by updating catalina.properties with: tomcat.util.scan.DefaultJarScanner.jarsToSkip=*.jar Rolled back to 7.0.25 ;) - Peter