1. With derby.system.durability=test,Test to see if syncs are not happening 
Is warning message about derby.system.durability=test present in derby.log =true
log.ctrl file has durability testMode no sync marker value = true
2. shutdown database and reboot database without derby.system.durability=test and test for marker in log.ctrl file
log.ctrl file has durability testMode no sync marker value = true
Is warning message about derby.system.durability=test present in derby.log =true
