Tomcat: “java.lang.OutOfMemoryError: PermGen space” error

solution:

create setenv.sh as follow and put it into $CANTLINA_HOME/bin

#!/bin/sh

JAVA_OPTS="-Xms256m -Xmx512m -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:MaxPermSize=256m"