The PHOENIX_JAVA_OPTS variable specifies the memory settings for the Java virtual machine that supports the site's ability to send and receive email and to index data for search.
Java specifications
-Xms256m -Xmx256m -server -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/tmp -verbose:gc -XX:+ PrintGCTimeStamps -XX:+PrintGCDetails -Dsun.rmi.dgc.client.gcInterval=600000 -Dsun.rmi.dgc.server.gcInterval=600000 -Dsf .luceneOptimizeEvery=100000 -Djava.security.egd=file:/dev/urandom