MySQL as DefaultDS in JBoss

cd $JBOSS_HOME
cp -r server/default server/defaultMySQL

cp docs/examples/jca/mysql-ds.xml server/defaultMySQL/deploy/
vi server/defaultMySQL/deploy/mysql-ds.xml

  <jndi-name>DefaultDS</jndi-name>
  <transaction-isolation>TRANSACTION_READ_COMMITTED</transaction-isolation>
  <connection-url>jdbc:mysql://localhost:3306/jbossdb</connection-url>
  <driver-class>com.mysql.jdbc.Driver</driver-class>
  <user-name>jbossdb</user-name>
  <password>jbossdb</password>

rm server/defaultMySQL/deploy/hsqldb-ds.xml


cp docs/examples/jms/mysql-persistence-service.xml server/defaultMySQL/deploy/messaging/
vi server/defaultMySQL/deploy/messaging/mysql-persistence-service.xml

<!-- disable 
  <depends optional-attribute-name="ChannelFactoryName">jboss.jgroups:service=ChannelFactory</depends>
-->

rm server/defaultMySQL/deploy/messaging/hsqldb-persistence-service.xml


Download JDBC Driver for MySQL (Connector/J)
http://www.mysql.com/products/connector/
untar/unzip it and extract the jar file
cp mysql-connector-java-5.1.7-bin.jar $JBOSS_HOME/server/defaultMySQL/lib/mysql-connector-java-5.1.7-bin.jar

$JBOSS_HOME/bin/run.sh -c defaultMySQL