i just go to <JBOSSFUSE620>/instances/child/bin, put export KARAF_DEBUG=true entry at <JBOSSFUSE620>/instances/child/bin/karaf file but it doesnot work

how do i debug my bundle on child instance?there are two files under <JBOSSFUSE620>//instances/child/bin , one is karaf another is start, what are different? Which file will be called during child instance starting?

  Any hints will be more than welcomed.