Does anyone know or know how to find the default values for the various memory allocation-related parameters (-Xms, -Xms, -XX:PermSize, -XX:MaxPermSize) for Tomcat version 6?
As far as I can tell the defaults should be the same as for any server JVM. Are you using the default Sun/Oracle JDK, version 6?
If so you could check the default values.
Of course, if this particular Tomcat install is new to you remember to check the actual JVM parameters using
ps auxwwe (if using Linux) and its init scripts in case someone set CATALINA_OPTS or JAVA_OPTS, etc.