Customizing the WebLogic JVM heap size
You can change the default JVM heap size to fit the needs of your deployment.
The default JVM heap size for WebLogic is 3GB. The size is set in the setDomainEnv.sh file for Linux or setDomainEnv.cmd for Windows, which is in the $DOMAIN_HOME/bin directory. The heap size is set with the -Xmx option.
To change the WebLogic JVM heap size: