I have enabled JPA 2.0 on a Unix-based system using a variation on the 'Installing Manually' steps in the Oracle doc you referenced. The key is to add the two JPA jars at the beginning of the classpath. In my case, we wanted JPA 2.0 support for a single managed server in the domain, so I added the following hack at the beginning of the setDomainEnv.sh script:
if [ "${SERVER_NAME}" = "TEST_Server1" ] ; then
JPA20="path/modules/javax.persistence_1.1.0.0_2-0.jar${CLASSPATHSEP}path/modules/com.oracle.jpa2support_1.0.0.0_2-1.jar"
if [ "${PRE_CLASSPATH}" != "" ] ; then
PRE_CLASSPATH="${JPA20}${CLASSPATHSEP}${PRE_CLASSPATH}"
export PRE_CLASSPATH
else
PRE_CLASSPATH="${JPA20}"
export PRE_CLASSPATH
fi
fi
Adjust the TEST_Server1
name (or just remove the if) and path
references to align with your environment.