How to configure Java Virtual Machine (JVM) settings in JBoss Enterprise Platform 6 (EAP 6) ?

Issue

• How to configure Java Virtual Machine (JVM) settings in JBoss Enterprise Platform 6 (EAP 6) ?
• How to customize JAVA_OPTS such as AggressiveOpts and UseParallelGC in standalone and domain mode ?
• Managed servers not started in 64 bit mode .
• How to configure JVM settings in domain.xml file ?
• Tried to set JAVA_OPTS in domain.conf/domain.sh, but somehow the values are not getting picked up by the server after server start up.
  Getting following error while starting JBoss server on domain mode :

22:13:02,763 ERROR [org.jboss.as.process.Server:server-one.status] (ProcessController-threads - 3) JBAS012006: Failed to send data bytes to process 'Server:server-one' input stream: java.io.IOException: Broken pipe
    at java.io.FileOutputStream.writeBytes(Native Method) [rt.jar:1.6.0_30]
    at java.io.FileOutputStream.write(FileOutputStream.java:282) [rt.jar:1.6.0_30]
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65) [rt.jar:1.6.0_30]
    at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123) [rt.jar:1.6.0_30]
    at org.jboss.as.process.ManagedProcess.sendStdin(ManagedProcess.java:160) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.ProcessController.sendStdin(ProcessController.java:183) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.ProcessControllerServerHandler$InitMessageHandler$ConnectedMessageHandler.handleMessage(ProcessControllerServerHandler.java:140) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.protocol.ConnectionImpl.safeHandleMessage(ConnectionImpl.java:269) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.protocol.ConnectionImpl$1$1.run(ConnectionImpl.java:223) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_30]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_30]
    at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_30]
    at org.jboss.threads.JBossThread.run(JBossThread.java:122) [jboss-threads-2.1.0.Final-redhat-1.jar:2.1.0.Final-redhat-1]

22:13:02,766 ERROR [org.jboss.as.protocol.connection] (ProcessController-threads - 3) JBAS016610: Failed to read a message: java.io.IOException: Broken pipe
    at java.io.FileOutputStream.writeBytes(Native Method) [rt.jar:1.6.0_30]
    at java.io.FileOutputStream.write(FileOutputStream.java:282) [rt.jar:1.6.0_30]
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65) [rt.jar:1.6.0_30]
    at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123) [rt.jar:1.6.0_30]
    at org.jboss.as.process.ManagedProcess.sendStdin(ManagedProcess.java:160) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.ProcessController.sendStdin(ProcessController.java:183) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.ProcessControllerServerHandler$InitMessageHandler$ConnectedMessageHandler.handleMessage(ProcessControllerServerHandler.java:140) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.protocol.ConnectionImpl.safeHandleMessage(ConnectionImpl.java:269) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at org.jboss.as.process.protocol.ConnectionImpl$1$1.run(ConnectionImpl.java:223) [jboss-as-process-controller-7.2.0.Final-redhat-8.jar:7.2.0.Final-redhat-8]
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [rt.jar:1.6.0_30]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [rt.jar:1.6.0_30]
    at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_30]
    at org.jboss.threads.JBossThread.run(JBossThread.java:122) [jboss-threads-2.1.0.Final-redhat-1.jar:2.1.0.Final-redhat-1]
22:13:02,847 INFO  [org.jboss.as.process.Server:server-two.status] (ProcessController-threads - 4) JBAS012017: Starting process 'Server:server-two'
[Server:server-two] Unrecognized option: -server -d64
[Server:server-two] Could not create the Java virtual machine.