I have experienced a problem where, for whatever reason, a
     specific-volume tape mount cannot be satisfied and I cannot cancel the
     process requesting it.

     One example is when our tape library is over-zealous and picks tapes
     for offsite vaulting between the time that a tape is created and when
     it is marked offsite to ADSM (then we subsequently try to write to
     it).  Another incident occurred when the bar code label on the
     cartridge wasn't being recognized by our STK silos.

     In any case, I have never been able to cancel the process.  We end up
     recycling the ADSM address space (killing any backup sessions that
     might happen to be active).

     Is there an answer to this?