When your job failed with 'Resource unavailable' IRLM tracked a record about the lock situation. Try searching the log for message DSNI031I.
Here you can find some additional information about the message:
http://www-01.ibm.com/support/knowledge ... i031i.ditaHere you may find some helpful information about locks escalation:
http://www-01.ibm.com/support/knowledge ... ation.dita