Here's my full JAVA OPTS configuration:
JAVA_OPTS="-Xms2g -Xmx2g -XX:NewSize=1g -XX:MaxNewSize=1g -XX:PermSize=256m -XX:MaxPermSize=256m -Xss256k -server -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -Xloggc:/X/X/X.log -XX:+UseParallelGC -XX:+UseParallelOldGC -XX:ParallelGCThreads=4 -XX:+AggressiveHeap -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/X/X/X -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000"