#### To configure the JVM settings

The Java Virtual Machine (JVM) is included in the Java 2 Standard Edition (J2SETM) software, which is required by the Application Server. Because incorrect JVM settings will prevent the server from running, you should take care when changing these settings.

1. In the Developer profile, select the Application Server node.
2. In the Cluster and Enterprise profile, select the Configurations node Cluster.
3. Click the JVM Settings tab.
4. From the JVM Settings General tab, define the following settings:

   - Java Home: Enter the name of the installation directory of the Java Standard Edition (SE) software. The Application Server relies on Java SE. To verify that the Java SE version you specify is supported in this release, see Sun Java System Application Server 9.1 Release Notes.

     Note - If you enter a nonexistent directory name or the directory for an unsupported version of the Java SE, then Application Server will not start.

   - Javac Options: Enter the command-line options for the Java programming language compiler. The Application Server runs the compiler when EJB components are deployed.

   - Debug: To set up debugging with the JPDA (Java Platform Debugger Architecture), select this Enabled checkbox.

     JPDA is used by application developers. For more information, see Chapter 4, Debugging Applications, in Sun Java System Application Server 9.1 Developer’s Guide.

   - Debug Options: Specify the JPDA options passed to the JVM when the debugging is enabled.

   - RMI Compile Options: Enter the command-line options for the `rmic` compiler. The Application Server runs the `rmic` compiler when EJB components are deployed.

   - Bytecode Preprocessor: Enter a comma separated list of class names. Each class must implement the `com.sun.appserv.BytecodePreprocessor` interface. The classes are called in the order specified.

     Tools such as profilers may require entries in the Bytecode Preprocessor field. Profilers generate information used to analyze server performance. For more information about profiling, see Chapter 4, Debugging Applications, in Sun Java System Application Server 9.1 Developer’s Guide.

5. Click Save.
6. Restart the server.