How to increase Memory available to Tomcat?

[o haya]

Hi,

I am running Tomcat 9.02 under RHEL 7 (under Oracle JDK 1.8), and I would
like to increase the memory that is available to Tomcat when it is running.

I have tried sourcing the following:

JAVA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server \
-Xms4096m -Xmx4096m -XX:NewSize=256m -XX:MaxNewSize=256m
-XX:+DisableExplicitGC \
-Djava.security.egd=file:/dev/./urandom -d64"

and also:

CATALINA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 -server \
-Xms4096m -Xmx4096m -XX:NewSize=256m -XX:MaxNewSize=256m
-XX:+DisableExplicitGC \
-Djava.security.egd=file:/dev/./urandom"

but even with those, when I check memory using "free", it is only using
about 1.5GB.

Can someone tell me how I can accomplish this?

Thanks,
Jim