export JAVA_OPTS="$JAVA_OPTS -javaagent:PLUMBR_HOME/plumbr.jar -agentpath:PLUMBR_HOME/lib/linux/32/libplumbr.so"
or
export JAVA_OPTS="$JAVA_OPTS -javaagent:PLUMBR_HOME/plumbr.jar -agentpath:PLUMBR_HOME/lib/linux/64/libplumbr.so"

When everything went smoothly, you will see the following banner in the restarted JVM standard output and a new JVM appears in https://portal.plumbr.eu.

************************************************************
* Plumbr (15.01.4138) is attached.                         *
*                                                          *
* Plumbr agent is connected to the Plumbr Server.          *
* Open up https://portal.plumbr.eu to follow its progress. *
************************************************************